drivers/net/veth.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  drivers/net/veth.c
   4  *
   5  *  Copyright (C) 2007 OpenVZ http://openvz.org, SWsoft Inc
   6  *
   7  * Author: Pavel Emelianov <xemul@openvz.org>
   8  * Ethtool interface from: Eric W. Biederman <ebiederm@xmission.com>
   9  *
  10  */
  11
  12 #include <linux/netdevice.h>
  13 #include <linux/slab.h>
  14 #include <linux/ethtool.h>
  15 #include <linux/etherdevice.h>
  16 #include <linux/u64_stats_sync.h>
  17
  18 #include <net/rtnetlink.h>
  19 #include <net/dst.h>
  20 #include <net/xfrm.h>
  21 #include <net/xdp.h>
  22 #include <linux/veth.h>
  23 #include <linux/module.h>
  24 #include <linux/bpf.h>
  25 #include <linux/filter.h>
  26 #include <linux/ptr_ring.h>
  27 #include <linux/bpf_trace.h>
  28 #include <linux/net_tstamp.h>
  29 #include <net/page_pool/helpers.h>
  30
  31 #define DRV_NAME        "veth"
  32 #define DRV_VERSION     "1.0"
  33
  34 #define VETH_XDP_FLAG           BIT(0)
  35 #define VETH_RING_SIZE          256
  36 #define VETH_XDP_HEADROOM       (XDP_PACKET_HEADROOM + NET_IP_ALIGN)
  37
  38 #define VETH_XDP_TX_BULK_SIZE   16
  39 #define VETH_XDP_BATCH          16
  40
  41 struct veth_stats {
  42         u64     rx_drops;
  43         /* xdp */
  44         u64     xdp_packets;
  45         u64     xdp_bytes;
  46         u64     xdp_redirect;
  47         u64     xdp_drops;
  48         u64     xdp_tx;
  49         u64     xdp_tx_err;
  50         u64     peer_tq_xdp_xmit;
  51         u64     peer_tq_xdp_xmit_err;
  52 };
  53
  54 struct veth_rq_stats {
  55         struct veth_stats       vs;
  56         struct u64_stats_sync   syncp;
  57 };
  58
  59 struct veth_rq {
  60         struct napi_struct      xdp_napi;
  61         struct napi_struct __rcu *napi; /* points to xdp_napi when the latter is initialized */
  62         struct net_device       *dev;
  63         struct bpf_prog __rcu   *xdp_prog;
  64         struct xdp_mem_info     xdp_mem;
  65         struct veth_rq_stats    stats;
  66         bool                    rx_notify_masked;
  67         struct ptr_ring         xdp_ring;
  68         struct xdp_rxq_info     xdp_rxq;
  69         struct page_pool        *page_pool;
  70 };
  71
  72 struct veth_priv {
  73         struct net_device __rcu *peer;
  74         atomic64_t              dropped;
  75         struct bpf_prog         *_xdp_prog;
  76         struct veth_rq          *rq;
  77         unsigned int            requested_headroom;
  78 };
  79
  80 struct veth_xdp_tx_bq {
  81         struct xdp_frame *q[VETH_XDP_TX_BULK_SIZE];
  82         unsigned int count;
  83 };
  84
  85 /*
  86  * ethtool interface
  87  */
  88
  89 struct veth_q_stat_desc {
  90         char    desc[ETH_GSTRING_LEN];
  91         size_t  offset;
  92 };
  93
  94 #define VETH_RQ_STAT(m) offsetof(struct veth_stats, m)
  95
  96 static const struct veth_q_stat_desc veth_rq_stats_desc[] = {
  97         { "xdp_packets",        VETH_RQ_STAT(xdp_packets) },
  98         { "xdp_bytes",          VETH_RQ_STAT(xdp_bytes) },
  99         { "drops",              VETH_RQ_STAT(rx_drops) },
 100         { "xdp_redirect",       VETH_RQ_STAT(xdp_redirect) },
 101         { "xdp_drops",          VETH_RQ_STAT(xdp_drops) },
 102         { "xdp_tx",             VETH_RQ_STAT(xdp_tx) },
 103         { "xdp_tx_errors",      VETH_RQ_STAT(xdp_tx_err) },
 104 };
 105
 106 #define VETH_RQ_STATS_LEN       ARRAY_SIZE(veth_rq_stats_desc)
 107
 108 static const struct veth_q_stat_desc veth_tq_stats_desc[] = {
 109         { "xdp_xmit",           VETH_RQ_STAT(peer_tq_xdp_xmit) },
 110         { "xdp_xmit_errors",    VETH_RQ_STAT(peer_tq_xdp_xmit_err) },
 111 };
 112
 113 #define VETH_TQ_STATS_LEN       ARRAY_SIZE(veth_tq_stats_desc)
 114
 115 static struct {
 116         const char string[ETH_GSTRING_LEN];
 117 } ethtool_stats_keys[] = {
 118         { "peer_ifindex" },
 119 };
 120
 121 struct veth_xdp_buff {
 122         struct xdp_buff xdp;
 123         struct sk_buff *skb;
 124 };
 125
 126 static int veth_get_link_ksettings(struct net_device *dev,
 127                                    struct ethtool_link_ksettings *cmd)
 128 {
 129         cmd->base.speed         = SPEED_10000;
 130         cmd->base.duplex        = DUPLEX_FULL;
 131         cmd->base.port          = PORT_TP;
 132         cmd->base.autoneg       = AUTONEG_DISABLE;
 133         return 0;
 134 }
 135
 136 static void veth_get_drvinfo(struct net_device *dev, struct ethtool_drvinfo *info)
 137 {
 138         strscpy(info->driver, DRV_NAME, sizeof(info->driver));
 139         strscpy(info->version, DRV_VERSION, sizeof(info->version));
 140 }
 141
 142 static void veth_get_strings(struct net_device *dev, u32 stringset, u8 *buf)
 143 {
 144         u8 *p = buf;
 145         int i, j;
 146
 147         switch(stringset) {
 148         case ETH_SS_STATS:
 149                 memcpy(p, &ethtool_stats_keys, sizeof(ethtool_stats_keys));
 150                 p += sizeof(ethtool_stats_keys);
 151                 for (i = 0; i < dev->real_num_rx_queues; i++)
 152                         for (j = 0; j < VETH_RQ_STATS_LEN; j++)
 153                                 ethtool_sprintf(&p, "rx_queue_%u_%.18s",
 154                                                 i, veth_rq_stats_desc[j].desc);
 155
 156                 for (i = 0; i < dev->real_num_tx_queues; i++)
 157                         for (j = 0; j < VETH_TQ_STATS_LEN; j++)
 158                                 ethtool_sprintf(&p, "tx_queue_%u_%.18s",
 159                                                 i, veth_tq_stats_desc[j].desc);
 160
 161                 page_pool_ethtool_stats_get_strings(p);
 162                 break;
 163         }
 164 }
 165
 166 static int veth_get_sset_count(struct net_device *dev, int sset)
 167 {
 168         switch (sset) {
 169         case ETH_SS_STATS:
 170                 return ARRAY_SIZE(ethtool_stats_keys) +
 171                        VETH_RQ_STATS_LEN * dev->real_num_rx_queues +
 172                        VETH_TQ_STATS_LEN * dev->real_num_tx_queues +
 173                        page_pool_ethtool_stats_get_count();
 174         default:
 175                 return -EOPNOTSUPP;
 176         }
 177 }
 178
 179 static void veth_get_page_pool_stats(struct net_device *dev, u64 *data)
 180 {
 181 #ifdef CONFIG_PAGE_POOL_STATS
 182         struct veth_priv *priv = netdev_priv(dev);
 183         struct page_pool_stats pp_stats = {};
 184         int i;
 185
 186         for (i = 0; i < dev->real_num_rx_queues; i++) {
 187                 if (!priv->rq[i].page_pool)
 188                         continue;
 189                 page_pool_get_stats(priv->rq[i].page_pool, &pp_stats);
 190         }
 191         page_pool_ethtool_stats_get(data, &pp_stats);
 192 #endif /* CONFIG_PAGE_POOL_STATS */
 193 }
 194
 195 static void veth_get_ethtool_stats(struct net_device *dev,
 196                 struct ethtool_stats *stats, u64 *data)
 197 {
 198         struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 199         struct net_device *peer = rtnl_dereference(priv->peer);
 200         int i, j, idx, pp_idx;
 201
 202         data[0] = peer ? peer->ifindex : 0;
 203         idx = 1;
 204         for (i = 0; i < dev->real_num_rx_queues; i++) {
 205                 const struct veth_rq_stats *rq_stats = &priv->rq[i].stats;
 206                 const void *stats_base = (void *)&rq_stats->vs;
 207                 unsigned int start;
 208                 size_t offset;
 209
 210                 do {
 211                         start = u64_stats_fetch_begin(&rq_stats->syncp);
 212                         for (j = 0; j < VETH_RQ_STATS_LEN; j++) {
 213                                 offset = veth_rq_stats_desc[j].offset;
 214                                 data[idx + j] = *(u64 *)(stats_base + offset);
 215                         }
 216                 } while (u64_stats_fetch_retry(&rq_stats->syncp, start));
 217                 idx += VETH_RQ_STATS_LEN;
 218         }
 219         pp_idx = idx;
 220
 221         if (!peer)
 222                 goto page_pool_stats;
 223
 224         rcv_priv = netdev_priv(peer);
 225         for (i = 0; i < peer->real_num_rx_queues; i++) {
 226                 const struct veth_rq_stats *rq_stats = &rcv_priv->rq[i].stats;
 227                 const void *base = (void *)&rq_stats->vs;
 228                 unsigned int start, tx_idx = idx;
 229                 size_t offset;
 230
 231                 tx_idx += (i % dev->real_num_tx_queues) * VETH_TQ_STATS_LEN;
 232                 do {
 233                         start = u64_stats_fetch_begin(&rq_stats->syncp);
 234                         for (j = 0; j < VETH_TQ_STATS_LEN; j++) {
 235                                 offset = veth_tq_stats_desc[j].offset;
 236                                 data[tx_idx + j] += *(u64 *)(base + offset);
 237                         }
 238                 } while (u64_stats_fetch_retry(&rq_stats->syncp, start));
 239                 pp_idx = tx_idx + VETH_TQ_STATS_LEN;
 240         }
 241
 242 page_pool_stats:
 243         veth_get_page_pool_stats(dev, &data[pp_idx]);
 244 }
 245
 246 static void veth_get_channels(struct net_device *dev,
 247                               struct ethtool_channels *channels)
 248 {
 249         channels->tx_count = dev->real_num_tx_queues;
 250         channels->rx_count = dev->real_num_rx_queues;
 251         channels->max_tx = dev->num_tx_queues;
 252         channels->max_rx = dev->num_rx_queues;
 253 }
 254
 255 static int veth_set_channels(struct net_device *dev,
 256                              struct ethtool_channels *ch);
 257
 258 static const struct ethtool_ops veth_ethtool_ops = {
 259         .get_drvinfo            = veth_get_drvinfo,
 260         .get_link               = ethtool_op_get_link,
 261         .get_strings            = veth_get_strings,
 262         .get_sset_count         = veth_get_sset_count,
 263         .get_ethtool_stats      = veth_get_ethtool_stats,
 264         .get_link_ksettings     = veth_get_link_ksettings,
 265         .get_ts_info            = ethtool_op_get_ts_info,
 266         .get_channels           = veth_get_channels,
 267         .set_channels           = veth_set_channels,
 268 };
 269
 270 /* general routines */
 271
 272 static bool veth_is_xdp_frame(void *ptr)
 273 {
 274         return (unsigned long)ptr & VETH_XDP_FLAG;
 275 }
 276
 277 static struct xdp_frame *veth_ptr_to_xdp(void *ptr)
 278 {
 279         return (void *)((unsigned long)ptr & ~VETH_XDP_FLAG);
 280 }
 281
 282 static void *veth_xdp_to_ptr(struct xdp_frame *xdp)
 283 {
 284         return (void *)((unsigned long)xdp | VETH_XDP_FLAG);
 285 }
 286
 287 static void veth_ptr_free(void *ptr)
 288 {
 289         if (veth_is_xdp_frame(ptr))
 290                 xdp_return_frame(veth_ptr_to_xdp(ptr));
 291         else
 292                 kfree_skb(ptr);
 293 }
 294
 295 static void __veth_xdp_flush(struct veth_rq *rq)
 296 {
 297         /* Write ptr_ring before reading rx_notify_masked */
 298         smp_mb();
 299         if (!READ_ONCE(rq->rx_notify_masked) &&
 300             napi_schedule_prep(&rq->xdp_napi)) {
 301                 WRITE_ONCE(rq->rx_notify_masked, true);
 302                 __napi_schedule(&rq->xdp_napi);
 303         }
 304 }
 305
 306 static int veth_xdp_rx(struct veth_rq *rq, struct sk_buff *skb)
 307 {
 308         if (unlikely(ptr_ring_produce(&rq->xdp_ring, skb))) {
 309                 dev_kfree_skb_any(skb);
 310                 return NET_RX_DROP;
 311         }
 312
 313         return NET_RX_SUCCESS;
 314 }
 315
 316 static int veth_forward_skb(struct net_device *dev, struct sk_buff *skb,
 317                             struct veth_rq *rq, bool xdp)
 318 {
 319         return __dev_forward_skb(dev, skb) ?: xdp ?
 320                 veth_xdp_rx(rq, skb) :
 321                 __netif_rx(skb);
 322 }
 323
 324 /* return true if the specified skb has chances of GRO aggregation
 325  * Don't strive for accuracy, but try to avoid GRO overhead in the most
 326  * common scenarios.
 327  * When XDP is enabled, all traffic is considered eligible, as the xmit
 328  * device has TSO off.
 329  * When TSO is enabled on the xmit device, we are likely interested only
 330  * in UDP aggregation, explicitly check for that if the skb is suspected
 331  * - the sock_wfree destructor is used by UDP, ICMP and XDP sockets -
 332  * to belong to locally generated UDP traffic.
 333  */
 334 static bool veth_skb_is_eligible_for_gro(const struct net_device *dev,
 335                                          const struct net_device *rcv,
 336                                          const struct sk_buff *skb)
 337 {
 338         return !(dev->features & NETIF_F_ALL_TSO) ||
 339                 (skb->destructor == sock_wfree &&
 340                  rcv->features & (NETIF_F_GRO_FRAGLIST | NETIF_F_GRO_UDP_FWD));
 341 }
 342
 343 static netdev_tx_t veth_xmit(struct sk_buff *skb, struct net_device *dev)
 344 {
 345         struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 346         struct veth_rq *rq = NULL;
 347         int ret = NETDEV_TX_OK;
 348         struct net_device *rcv;
 349         int length = skb->len;
 350         bool use_napi = false;
 351         int rxq;
 352
 353         rcu_read_lock();
 354         rcv = rcu_dereference(priv->peer);
 355         if (unlikely(!rcv) || !pskb_may_pull(skb, ETH_HLEN)) {
 356                 kfree_skb(skb);
 357                 goto drop;
 358         }
 359
 360         rcv_priv = netdev_priv(rcv);
 361         rxq = skb_get_queue_mapping(skb);
 362         if (rxq < rcv->real_num_rx_queues) {
 363                 rq = &rcv_priv->rq[rxq];
 364
 365                 /* The napi pointer is available when an XDP program is
 366                  * attached or when GRO is enabled
 367                  * Don't bother with napi/GRO if the skb can't be aggregated
 368                  */
 369                 use_napi = rcu_access_pointer(rq->napi) &&
 370                            veth_skb_is_eligible_for_gro(dev, rcv, skb);
 371         }
 372
 373         skb_tx_timestamp(skb);
 374         if (likely(veth_forward_skb(rcv, skb, rq, use_napi) == NET_RX_SUCCESS)) {
 375                 if (!use_napi)
 376                         dev_lstats_add(dev, length);
 377                 else
 378                         __veth_xdp_flush(rq);
 379         } else {
 380 drop:
 381                 atomic64_inc(&priv->dropped);
 382                 ret = NET_XMIT_DROP;
 383         }
 384
 385         rcu_read_unlock();
 386
 387         return ret;
 388 }
 389
 390 static u64 veth_stats_tx(struct net_device *dev, u64 *packets, u64 *bytes)
 391 {
 392         struct veth_priv *priv = netdev_priv(dev);
 393
 394         dev_lstats_read(dev, packets, bytes);
 395         return atomic64_read(&priv->dropped);
 396 }
 397
 398 static void veth_stats_rx(struct veth_stats *result, struct net_device *dev)
 399 {
 400         struct veth_priv *priv = netdev_priv(dev);
 401         int i;
 402
 403         result->peer_tq_xdp_xmit_err = 0;
 404         result->xdp_packets = 0;
 405         result->xdp_tx_err = 0;
 406         result->xdp_bytes = 0;
 407         result->rx_drops = 0;
 408         for (i = 0; i < dev->num_rx_queues; i++) {
 409                 u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err;
 410                 struct veth_rq_stats *stats = &priv->rq[i].stats;
 411                 unsigned int start;
 412
 413                 do {
 414                         start = u64_stats_fetch_begin(&stats->syncp);
 415                         peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err;
 416                         xdp_tx_err = stats->vs.xdp_tx_err;
 417                         packets = stats->vs.xdp_packets;
 418                         bytes = stats->vs.xdp_bytes;
 419                         drops = stats->vs.rx_drops;
 420                 } while (u64_stats_fetch_retry(&stats->syncp, start));
 421                 result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err;
 422                 result->xdp_tx_err += xdp_tx_err;
 423                 result->xdp_packets += packets;
 424                 result->xdp_bytes += bytes;
 425                 result->rx_drops += drops;
 426         }
 427 }
 428
 429 static void veth_get_stats64(struct net_device *dev,
 430                              struct rtnl_link_stats64 *tot)
 431 {
 432         struct veth_priv *priv = netdev_priv(dev);
 433         struct net_device *peer;
 434         struct veth_stats rx;
 435         u64 packets, bytes;
 436
 437         tot->tx_dropped = veth_stats_tx(dev, &packets, &bytes);
 438         tot->tx_bytes = bytes;
 439         tot->tx_packets = packets;
 440
 441         veth_stats_rx(&rx, dev);
 442         tot->tx_dropped += rx.xdp_tx_err;
 443         tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err;
 444         tot->rx_bytes = rx.xdp_bytes;
 445         tot->rx_packets = rx.xdp_packets;
 446
 447         rcu_read_lock();
 448         peer = rcu_dereference(priv->peer);
 449         if (peer) {
 450                 veth_stats_tx(peer, &packets, &bytes);
 451                 tot->rx_bytes += bytes;
 452                 tot->rx_packets += packets;
 453
 454                 veth_stats_rx(&rx, peer);
 455                 tot->tx_dropped += rx.peer_tq_xdp_xmit_err;
 456                 tot->rx_dropped += rx.xdp_tx_err;
 457                 tot->tx_bytes += rx.xdp_bytes;
 458                 tot->tx_packets += rx.xdp_packets;
 459         }
 460         rcu_read_unlock();
 461 }
 462
 463 /* fake multicast ability */
 464 static void veth_set_multicast_list(struct net_device *dev)
 465 {
 466 }
 467
 468 static int veth_select_rxq(struct net_device *dev)
 469 {
 470         return smp_processor_id() % dev->real_num_rx_queues;
 471 }
 472
 473 static struct net_device *veth_peer_dev(struct net_device *dev)
 474 {
 475         struct veth_priv *priv = netdev_priv(dev);
 476
 477         /* Callers must be under RCU read side. */
 478         return rcu_dereference(priv->peer);
 479 }
 480
 481 static int veth_xdp_xmit(struct net_device *dev, int n,
 482                          struct xdp_frame **frames,
 483                          u32 flags, bool ndo_xmit)
 484 {
 485         struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 486         int i, ret = -ENXIO, nxmit = 0;
 487         struct net_device *rcv;
 488         unsigned int max_len;
 489         struct veth_rq *rq;
 490
 491         if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
 492                 return -EINVAL;
 493
 494         rcu_read_lock();
 495         rcv = rcu_dereference(priv->peer);
 496         if (unlikely(!rcv))
 497                 goto out;
 498
 499         rcv_priv = netdev_priv(rcv);
 500         rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 501         /* The napi pointer is set if NAPI is enabled, which ensures that
 502          * xdp_ring is initialized on receive side and the peer device is up.
 503          */
 504         if (!rcu_access_pointer(rq->napi))
 505                 goto out;
 506
 507         max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
 508
 509         spin_lock(&rq->xdp_ring.producer_lock);
 510         for (i = 0; i < n; i++) {
 511                 struct xdp_frame *frame = frames[i];
 512                 void *ptr = veth_xdp_to_ptr(frame);
 513
 514                 if (unlikely(xdp_get_frame_len(frame) > max_len ||
 515                              __ptr_ring_produce(&rq->xdp_ring, ptr)))
 516                         break;
 517                 nxmit++;
 518         }
 519         spin_unlock(&rq->xdp_ring.producer_lock);
 520
 521         if (flags & XDP_XMIT_FLUSH)
 522                 __veth_xdp_flush(rq);
 523
 524         ret = nxmit;
 525         if (ndo_xmit) {
 526                 u64_stats_update_begin(&rq->stats.syncp);
 527                 rq->stats.vs.peer_tq_xdp_xmit += nxmit;
 528                 rq->stats.vs.peer_tq_xdp_xmit_err += n - nxmit;
 529                 u64_stats_update_end(&rq->stats.syncp);
 530         }
 531
 532 out:
 533         rcu_read_unlock();
 534
 535         return ret;
 536 }
 537
 538 static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
 539                              struct xdp_frame **frames, u32 flags)
 540 {
 541         int err;
 542
 543         err = veth_xdp_xmit(dev, n, frames, flags, true);
 544         if (err < 0) {
 545                 struct veth_priv *priv = netdev_priv(dev);
 546
 547                 atomic64_add(n, &priv->dropped);
 548         }
 549
 550         return err;
 551 }
 552
 553 static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 554 {
 555         int sent, i, err = 0, drops;
 556
 557         sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false);
 558         if (sent < 0) {
 559                 err = sent;
 560                 sent = 0;
 561         }
 562
 563         for (i = sent; unlikely(i < bq->count); i++)
 564                 xdp_return_frame(bq->q[i]);
 565
 566         drops = bq->count - sent;
 567         trace_xdp_bulk_tx(rq->dev, sent, drops, err);
 568
 569         u64_stats_update_begin(&rq->stats.syncp);
 570         rq->stats.vs.xdp_tx += sent;
 571         rq->stats.vs.xdp_tx_err += drops;
 572         u64_stats_update_end(&rq->stats.syncp);
 573
 574         bq->count = 0;
 575 }
 576
 577 static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 578 {
 579         struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev);
 580         struct net_device *rcv;
 581         struct veth_rq *rcv_rq;
 582
 583         rcu_read_lock();
 584         veth_xdp_flush_bq(rq, bq);
 585         rcv = rcu_dereference(priv->peer);
 586         if (unlikely(!rcv))
 587                 goto out;
 588
 589         rcv_priv = netdev_priv(rcv);
 590         rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 591         /* xdp_ring is initialized on receive side? */
 592         if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
 593                 goto out;
 594
 595         __veth_xdp_flush(rcv_rq);
 596 out:
 597         rcu_read_unlock();
 598 }
 599
 600 static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
 601                        struct veth_xdp_tx_bq *bq)
 602 {
 603         struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
 604
 605         if (unlikely(!frame))
 606                 return -EOVERFLOW;
 607
 608         if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
 609                 veth_xdp_flush_bq(rq, bq);
 610
 611         bq->q[bq->count++] = frame;
 612
 613         return 0;
 614 }
 615
 616 static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
 617                                           struct xdp_frame *frame,
 618                                           struct veth_xdp_tx_bq *bq,
 619                                           struct veth_stats *stats)
 620 {
 621         struct xdp_frame orig_frame;
 622         struct bpf_prog *xdp_prog;
 623
 624         rcu_read_lock();
 625         xdp_prog = rcu_dereference(rq->xdp_prog);
 626         if (likely(xdp_prog)) {
 627                 struct veth_xdp_buff vxbuf;
 628                 struct xdp_buff *xdp = &vxbuf.xdp;
 629                 u32 act;
 630
 631                 xdp_convert_frame_to_buff(frame, xdp);
 632                 xdp->rxq = &rq->xdp_rxq;
 633                 vxbuf.skb = NULL;
 634
 635                 act = bpf_prog_run_xdp(xdp_prog, xdp);
 636
 637                 switch (act) {
 638                 case XDP_PASS:
 639                         if (xdp_update_frame_from_buff(xdp, frame))
 640                                 goto err_xdp;
 641                         break;
 642                 case XDP_TX:
 643                         orig_frame = *frame;
 644                         xdp->rxq->mem = frame->mem;
 645                         if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
 646                                 trace_xdp_exception(rq->dev, xdp_prog, act);
 647                                 frame = &orig_frame;
 648                                 stats->rx_drops++;
 649                                 goto err_xdp;
 650                         }
 651                         stats->xdp_tx++;
 652                         rcu_read_unlock();
 653                         goto xdp_xmit;
 654                 case XDP_REDIRECT:
 655                         orig_frame = *frame;
 656                         xdp->rxq->mem = frame->mem;
 657                         if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
 658                                 frame = &orig_frame;
 659                                 stats->rx_drops++;
 660                                 goto err_xdp;
 661                         }
 662                         stats->xdp_redirect++;
 663                         rcu_read_unlock();
 664                         goto xdp_xmit;
 665                 default:
 666                         bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 667                         fallthrough;
 668                 case XDP_ABORTED:
 669                         trace_xdp_exception(rq->dev, xdp_prog, act);
 670                         fallthrough;
 671                 case XDP_DROP:
 672                         stats->xdp_drops++;
 673                         goto err_xdp;
 674                 }
 675         }
 676         rcu_read_unlock();
 677
 678         return frame;
 679 err_xdp:
 680         rcu_read_unlock();
 681         xdp_return_frame(frame);
 682 xdp_xmit:
 683         return NULL;
 684 }
 685
 686 /* frames array contains VETH_XDP_BATCH at most */
 687 static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames,
 688                                   int n_xdpf, struct veth_xdp_tx_bq *bq,
 689                                   struct veth_stats *stats)
 690 {
 691         void *skbs[VETH_XDP_BATCH];
 692         int i;
 693
 694         if (xdp_alloc_skb_bulk(skbs, n_xdpf,
 695                                GFP_ATOMIC | __GFP_ZERO) < 0) {
 696                 for (i = 0; i < n_xdpf; i++)
 697                         xdp_return_frame(frames[i]);
 698                 stats->rx_drops += n_xdpf;
 699
 700                 return;
 701         }
 702
 703         for (i = 0; i < n_xdpf; i++) {
 704                 struct sk_buff *skb = skbs[i];
 705
 706                 skb = __xdp_build_skb_from_frame(frames[i], skb,
 707                                                  rq->dev);
 708                 if (!skb) {
 709                         xdp_return_frame(frames[i]);
 710                         stats->rx_drops++;
 711                         continue;
 712                 }
 713                 napi_gro_receive(&rq->xdp_napi, skb);
 714         }
 715 }
 716
 717 static void veth_xdp_get(struct xdp_buff *xdp)
 718 {
 719         struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
 720         int i;
 721
 722         get_page(virt_to_page(xdp->data));
 723         if (likely(!xdp_buff_has_frags(xdp)))
 724                 return;
 725
 726         for (i = 0; i < sinfo->nr_frags; i++)
 727                 __skb_frag_ref(&sinfo->frags[i]);
 728 }
 729
 730 static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
 731                                         struct xdp_buff *xdp,
 732                                         struct sk_buff **pskb)
 733 {
 734         struct sk_buff *skb = *pskb;
 735         u32 frame_sz;
 736
 737         if (skb_shared(skb) || skb_head_is_locked(skb) ||
 738             skb_shinfo(skb)->nr_frags ||
 739             skb_headroom(skb) < XDP_PACKET_HEADROOM) {
 740                 u32 size, len, max_head_size, off, truesize, page_offset;
 741                 struct sk_buff *nskb;
 742                 struct page *page;
 743                 int i, head_off;
 744                 void *va;
 745
 746                 /* We need a private copy of the skb and data buffers since
 747                  * the ebpf program can modify it. We segment the original skb
 748                  * into order-0 pages without linearize it.
 749                  *
 750                  * Make sure we have enough space for linear and paged area
 751                  */
 752                 max_head_size = SKB_WITH_OVERHEAD(PAGE_SIZE -
 753                                                   VETH_XDP_HEADROOM);
 754                 if (skb->len > PAGE_SIZE * MAX_SKB_FRAGS + max_head_size)
 755                         goto drop;
 756
 757                 size = min_t(u32, skb->len, max_head_size);
 758                 truesize = SKB_HEAD_ALIGN(size) + VETH_XDP_HEADROOM;
 759
 760                 /* Allocate skb head */
 761                 va = page_pool_dev_alloc_va(rq->page_pool, &truesize);
 762                 if (!va)
 763                         goto drop;
 764
 765                 nskb = napi_build_skb(va, truesize);
 766                 if (!nskb) {
 767                         page_pool_free_va(rq->page_pool, va, true);
 768                         goto drop;
 769                 }
 770
 771                 skb_reserve(nskb, VETH_XDP_HEADROOM);
 772                 skb_copy_header(nskb, skb);
 773                 skb_mark_for_recycle(nskb);
 774
 775                 if (skb_copy_bits(skb, 0, nskb->data, size)) {
 776                         consume_skb(nskb);
 777                         goto drop;
 778                 }
 779                 skb_put(nskb, size);
 780
 781                 head_off = skb_headroom(nskb) - skb_headroom(skb);
 782                 skb_headers_offset_update(nskb, head_off);
 783
 784                 /* Allocate paged area of new skb */
 785                 off = size;
 786                 len = skb->len - off;
 787
 788                 for (i = 0; i < MAX_SKB_FRAGS && off < skb->len; i++) {
 789                         size = min_t(u32, len, PAGE_SIZE);
 790                         truesize = size;
 791
 792                         page = page_pool_dev_alloc(rq->page_pool, &page_offset,
 793                                                    &truesize);
 794                         if (!page) {
 795                                 consume_skb(nskb);
 796                                 goto drop;
 797                         }
 798
 799                         skb_add_rx_frag(nskb, i, page, page_offset, size,
 800                                         truesize);
 801                         if (skb_copy_bits(skb, off, page_address(page),
 802                                           size)) {
 803                                 consume_skb(nskb);
 804                                 goto drop;
 805                         }
 806
 807                         len -= size;
 808                         off += size;
 809                 }
 810
 811                 consume_skb(skb);
 812                 skb = nskb;
 813         }
 814
 815         /* SKB "head" area always have tailroom for skb_shared_info */
 816         frame_sz = skb_end_pointer(skb) - skb->head;
 817         frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 818         xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq);
 819         xdp_prepare_buff(xdp, skb->head, skb_headroom(skb),
 820                          skb_headlen(skb), true);
 821
 822         if (skb_is_nonlinear(skb)) {
 823                 skb_shinfo(skb)->xdp_frags_size = skb->data_len;
 824                 xdp_buff_set_frags_flag(xdp);
 825         } else {
 826                 xdp_buff_clear_frags_flag(xdp);
 827         }
 828         *pskb = skb;
 829
 830         return 0;
 831 drop:
 832         consume_skb(skb);
 833         *pskb = NULL;
 834
 835         return -ENOMEM;
 836 }
 837
 838 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 839                                         struct sk_buff *skb,
 840                                         struct veth_xdp_tx_bq *bq,
 841                                         struct veth_stats *stats)
 842 {
 843         void *orig_data, *orig_data_end;
 844         struct bpf_prog *xdp_prog;
 845         struct veth_xdp_buff vxbuf;
 846         struct xdp_buff *xdp = &vxbuf.xdp;
 847         u32 act, metalen;
 848         int off;
 849
 850         skb_prepare_for_gro(skb);
 851
 852         rcu_read_lock();
 853         xdp_prog = rcu_dereference(rq->xdp_prog);
 854         if (unlikely(!xdp_prog)) {
 855                 rcu_read_unlock();
 856                 goto out;
 857         }
 858
 859         __skb_push(skb, skb->data - skb_mac_header(skb));
 860         if (veth_convert_skb_to_xdp_buff(rq, xdp, &skb))
 861                 goto drop;
 862         vxbuf.skb = skb;
 863
 864         orig_data = xdp->data;
 865         orig_data_end = xdp->data_end;
 866
 867         act = bpf_prog_run_xdp(xdp_prog, xdp);
 868
 869         switch (act) {
 870         case XDP_PASS:
 871                 break;
 872         case XDP_TX:
 873                 veth_xdp_get(xdp);
 874                 consume_skb(skb);
 875                 xdp->rxq->mem = rq->xdp_mem;
 876                 if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
 877                         trace_xdp_exception(rq->dev, xdp_prog, act);
 878                         stats->rx_drops++;
 879                         goto err_xdp;
 880                 }
 881                 stats->xdp_tx++;
 882                 rcu_read_unlock();
 883                 goto xdp_xmit;
 884         case XDP_REDIRECT:
 885                 veth_xdp_get(xdp);
 886                 consume_skb(skb);
 887                 xdp->rxq->mem = rq->xdp_mem;
 888                 if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
 889                         stats->rx_drops++;
 890                         goto err_xdp;
 891                 }
 892                 stats->xdp_redirect++;
 893                 rcu_read_unlock();
 894                 goto xdp_xmit;
 895         default:
 896                 bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 897                 fallthrough;
 898         case XDP_ABORTED:
 899                 trace_xdp_exception(rq->dev, xdp_prog, act);
 900                 fallthrough;
 901         case XDP_DROP:
 902                 stats->xdp_drops++;
 903                 goto xdp_drop;
 904         }
 905         rcu_read_unlock();
 906
 907         /* check if bpf_xdp_adjust_head was used */
 908         off = orig_data - xdp->data;
 909         if (off > 0)
 910                 __skb_push(skb, off);
 911         else if (off < 0)
 912                 __skb_pull(skb, -off);
 913
 914         skb_reset_mac_header(skb);
 915
 916         /* check if bpf_xdp_adjust_tail was used */
 917         off = xdp->data_end - orig_data_end;
 918         if (off != 0)
 919                 __skb_put(skb, off); /* positive on grow, negative on shrink */
 920
 921         /* XDP frag metadata (e.g. nr_frags) are updated in eBPF helpers
 922          * (e.g. bpf_xdp_adjust_tail), we need to update data_len here.
 923          */
 924         if (xdp_buff_has_frags(xdp))
 925                 skb->data_len = skb_shinfo(skb)->xdp_frags_size;
 926         else
 927                 skb->data_len = 0;
 928
 929         skb->protocol = eth_type_trans(skb, rq->dev);
 930
 931         metalen = xdp->data - xdp->data_meta;
 932         if (metalen)
 933                 skb_metadata_set(skb, metalen);
 934 out:
 935         return skb;
 936 drop:
 937         stats->rx_drops++;
 938 xdp_drop:
 939         rcu_read_unlock();
 940         kfree_skb(skb);
 941         return NULL;
 942 err_xdp:
 943         rcu_read_unlock();
 944         xdp_return_buff(xdp);
 945 xdp_xmit:
 946         return NULL;
 947 }
 948
 949 static int veth_xdp_rcv(struct veth_rq *rq, int budget,
 950                         struct veth_xdp_tx_bq *bq,
 951                         struct veth_stats *stats)
 952 {
 953         int i, done = 0, n_xdpf = 0;
 954         void *xdpf[VETH_XDP_BATCH];
 955
 956         for (i = 0; i < budget; i++) {
 957                 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
 958
 959                 if (!ptr)
 960                         break;
 961
 962                 if (veth_is_xdp_frame(ptr)) {
 963                         /* ndo_xdp_xmit */
 964                         struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
 965
 966                         stats->xdp_bytes += xdp_get_frame_len(frame);
 967                         frame = veth_xdp_rcv_one(rq, frame, bq, stats);
 968                         if (frame) {
 969                                 /* XDP_PASS */
 970                                 xdpf[n_xdpf++] = frame;
 971                                 if (n_xdpf == VETH_XDP_BATCH) {
 972                                         veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf,
 973                                                               bq, stats);
 974                                         n_xdpf = 0;
 975                                 }
 976                         }
 977                 } else {
 978                         /* ndo_start_xmit */
 979                         struct sk_buff *skb = ptr;
 980
 981                         stats->xdp_bytes += skb->len;
 982                         skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
 983                         if (skb) {
 984                                 if (skb_shared(skb) || skb_unclone(skb, GFP_ATOMIC))
 985                                         netif_receive_skb(skb);
 986                                 else
 987                                         napi_gro_receive(&rq->xdp_napi, skb);
 988                         }
 989                 }
 990                 done++;
 991         }
 992
 993         if (n_xdpf)
 994                 veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats);
 995
 996         u64_stats_update_begin(&rq->stats.syncp);
 997         rq->stats.vs.xdp_redirect += stats->xdp_redirect;
 998         rq->stats.vs.xdp_bytes += stats->xdp_bytes;
 999         rq->stats.vs.xdp_drops += stats->xdp_drops;
1000         rq->stats.vs.rx_drops += stats->rx_drops;
1001         rq->stats.vs.xdp_packets += done;
1002         u64_stats_update_end(&rq->stats.syncp);
1003
1004         return done;
1005 }
1006
1007 static int veth_poll(struct napi_struct *napi, int budget)
1008 {
1009         struct veth_rq *rq =
1010                 container_of(napi, struct veth_rq, xdp_napi);
1011         struct veth_stats stats = {};
1012         struct veth_xdp_tx_bq bq;
1013         int done;
1014
1015         bq.count = 0;
1016
1017         xdp_set_return_frame_no_direct();
1018         done = veth_xdp_rcv(rq, budget, &bq, &stats);
1019
1020         if (stats.xdp_redirect > 0)
1021                 xdp_do_flush();
1022
1023         if (done < budget && napi_complete_done(napi, done)) {
1024                 /* Write rx_notify_masked before reading ptr_ring */
1025                 smp_store_mb(rq->rx_notify_masked, false);
1026                 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
1027                         if (napi_schedule_prep(&rq->xdp_napi)) {
1028                                 WRITE_ONCE(rq->rx_notify_masked, true);
1029                                 __napi_schedule(&rq->xdp_napi);
1030                         }
1031                 }
1032         }
1033
1034         if (stats.xdp_tx > 0)
1035                 veth_xdp_flush(rq, &bq);
1036         xdp_clear_return_frame_no_direct();
1037
1038         return done;
1039 }
1040
1041 static int veth_create_page_pool(struct veth_rq *rq)
1042 {
1043         struct page_pool_params pp_params = {
1044                 .order = 0,
1045                 .pool_size = VETH_RING_SIZE,
1046                 .nid = NUMA_NO_NODE,
1047                 .dev = &rq->dev->dev,
1048         };
1049
1050         rq->page_pool = page_pool_create(&pp_params);
1051         if (IS_ERR(rq->page_pool)) {
1052                 int err = PTR_ERR(rq->page_pool);
1053
1054                 rq->page_pool = NULL;
1055                 return err;
1056         }
1057
1058         return 0;
1059 }
1060
1061 static int __veth_napi_enable_range(struct net_device *dev, int start, int end)
1062 {
1063         struct veth_priv *priv = netdev_priv(dev);
1064         int err, i;
1065
1066         for (i = start; i < end; i++) {
1067                 err = veth_create_page_pool(&priv->rq[i]);
1068                 if (err)
1069                         goto err_page_pool;
1070         }
1071
1072         for (i = start; i < end; i++) {
1073                 struct veth_rq *rq = &priv->rq[i];
1074
1075                 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
1076                 if (err)
1077                         goto err_xdp_ring;
1078         }
1079
1080         for (i = start; i < end; i++) {
1081                 struct veth_rq *rq = &priv->rq[i];
1082
1083                 napi_enable(&rq->xdp_napi);
1084                 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1085         }
1086
1087         return 0;
1088
1089 err_xdp_ring:
1090         for (i--; i >= start; i--)
1091                 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
1092         i = end;
1093 err_page_pool:
1094         for (i--; i >= start; i--) {
1095                 page_pool_destroy(priv->rq[i].page_pool);
1096                 priv->rq[i].page_pool = NULL;
1097         }
1098
1099         return err;
1100 }
1101
1102 static int __veth_napi_enable(struct net_device *dev)
1103 {
1104         return __veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1105 }
1106
1107 static void veth_napi_del_range(struct net_device *dev, int start, int end)
1108 {
1109         struct veth_priv *priv = netdev_priv(dev);
1110         int i;
1111
1112         for (i = start; i < end; i++) {
1113                 struct veth_rq *rq = &priv->rq[i];
1114
1115                 rcu_assign_pointer(priv->rq[i].napi, NULL);
1116                 napi_disable(&rq->xdp_napi);
1117                 __netif_napi_del(&rq->xdp_napi);
1118         }
1119         synchronize_net();
1120
1121         for (i = start; i < end; i++) {
1122                 struct veth_rq *rq = &priv->rq[i];
1123
1124                 rq->rx_notify_masked = false;
1125                 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
1126         }
1127
1128         for (i = start; i < end; i++) {
1129                 page_pool_destroy(priv->rq[i].page_pool);
1130                 priv->rq[i].page_pool = NULL;
1131         }
1132 }
1133
1134 static void veth_napi_del(struct net_device *dev)
1135 {
1136         veth_napi_del_range(dev, 0, dev->real_num_rx_queues);
1137 }
1138
1139 static bool veth_gro_requested(const struct net_device *dev)
1140 {
1141         return !!(dev->wanted_features & NETIF_F_GRO);
1142 }
1143
1144 static int veth_enable_xdp_range(struct net_device *dev, int start, int end,
1145                                  bool napi_already_on)
1146 {
1147         struct veth_priv *priv = netdev_priv(dev);
1148         int err, i;
1149
1150         for (i = start; i < end; i++) {
1151                 struct veth_rq *rq = &priv->rq[i];
1152
1153                 if (!napi_already_on)
1154                         netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1155                 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id);
1156                 if (err < 0)
1157                         goto err_rxq_reg;
1158
1159                 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
1160                                                  MEM_TYPE_PAGE_SHARED,
1161                                                  NULL);
1162                 if (err < 0)
1163                         goto err_reg_mem;
1164
1165                 /* Save original mem info as it can be overwritten */
1166                 rq->xdp_mem = rq->xdp_rxq.mem;
1167         }
1168         return 0;
1169
1170 err_reg_mem:
1171         xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
1172 err_rxq_reg:
1173         for (i--; i >= start; i--) {
1174                 struct veth_rq *rq = &priv->rq[i];
1175
1176                 xdp_rxq_info_unreg(&rq->xdp_rxq);
1177                 if (!napi_already_on)
1178                         netif_napi_del(&rq->xdp_napi);
1179         }
1180
1181         return err;
1182 }
1183
1184 static void veth_disable_xdp_range(struct net_device *dev, int start, int end,
1185                                    bool delete_napi)
1186 {
1187         struct veth_priv *priv = netdev_priv(dev);
1188         int i;
1189
1190         for (i = start; i < end; i++) {
1191                 struct veth_rq *rq = &priv->rq[i];
1192
1193                 rq->xdp_rxq.mem = rq->xdp_mem;
1194                 xdp_rxq_info_unreg(&rq->xdp_rxq);
1195
1196                 if (delete_napi)
1197                         netif_napi_del(&rq->xdp_napi);
1198         }
1199 }
1200
1201 static int veth_enable_xdp(struct net_device *dev)
1202 {
1203         bool napi_already_on = veth_gro_requested(dev) && (dev->flags & IFF_UP);
1204         struct veth_priv *priv = netdev_priv(dev);
1205         int err, i;
1206
1207         if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
1208                 err = veth_enable_xdp_range(dev, 0, dev->real_num_rx_queues, napi_already_on);
1209                 if (err)
1210                         return err;
1211
1212                 if (!napi_already_on) {
1213                         err = __veth_napi_enable(dev);
1214                         if (err) {
1215                                 veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, true);
1216                                 return err;
1217                         }
1218
1219                         if (!veth_gro_requested(dev)) {
1220                                 /* user-space did not require GRO, but adding XDP
1221                                  * is supposed to get GRO working
1222                                  */
1223                                 dev->features |= NETIF_F_GRO;
1224                                 netdev_features_change(dev);
1225                         }
1226                 }
1227         }
1228
1229         for (i = 0; i < dev->real_num_rx_queues; i++) {
1230                 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
1231                 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1232         }
1233
1234         return 0;
1235 }
1236
1237 static void veth_disable_xdp(struct net_device *dev)
1238 {
1239         struct veth_priv *priv = netdev_priv(dev);
1240         int i;
1241
1242         for (i = 0; i < dev->real_num_rx_queues; i++)
1243                 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
1244
1245         if (!netif_running(dev) || !veth_gro_requested(dev)) {
1246                 veth_napi_del(dev);
1247
1248                 /* if user-space did not require GRO, since adding XDP
1249                  * enabled it, clear it now
1250                  */
1251                 if (!veth_gro_requested(dev) && netif_running(dev)) {
1252                         dev->features &= ~NETIF_F_GRO;
1253                         netdev_features_change(dev);
1254                 }
1255         }
1256
1257         veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, false);
1258 }
1259
1260 static int veth_napi_enable_range(struct net_device *dev, int start, int end)
1261 {
1262         struct veth_priv *priv = netdev_priv(dev);
1263         int err, i;
1264
1265         for (i = start; i < end; i++) {
1266                 struct veth_rq *rq = &priv->rq[i];
1267
1268                 netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1269         }
1270
1271         err = __veth_napi_enable_range(dev, start, end);
1272         if (err) {
1273                 for (i = start; i < end; i++) {
1274                         struct veth_rq *rq = &priv->rq[i];
1275
1276                         netif_napi_del(&rq->xdp_napi);
1277                 }
1278                 return err;
1279         }
1280         return err;
1281 }
1282
1283 static int veth_napi_enable(struct net_device *dev)
1284 {
1285         return veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1286 }
1287
1288 static void veth_disable_range_safe(struct net_device *dev, int start, int end)
1289 {
1290         struct veth_priv *priv = netdev_priv(dev);
1291
1292         if (start >= end)
1293                 return;
1294
1295         if (priv->_xdp_prog) {
1296                 veth_napi_del_range(dev, start, end);
1297                 veth_disable_xdp_range(dev, start, end, false);
1298         } else if (veth_gro_requested(dev)) {
1299                 veth_napi_del_range(dev, start, end);
1300         }
1301 }
1302
1303 static int veth_enable_range_safe(struct net_device *dev, int start, int end)
1304 {
1305         struct veth_priv *priv = netdev_priv(dev);
1306         int err;
1307
1308         if (start >= end)
1309                 return 0;
1310
1311         if (priv->_xdp_prog) {
1312                 /* these channels are freshly initialized, napi is not on there even
1313                  * when GRO is requeste
1314                  */
1315                 err = veth_enable_xdp_range(dev, start, end, false);
1316                 if (err)
1317                         return err;
1318
1319                 err = __veth_napi_enable_range(dev, start, end);
1320                 if (err) {
1321                         /* on error always delete the newly added napis */
1322                         veth_disable_xdp_range(dev, start, end, true);
1323                         return err;
1324                 }
1325         } else if (veth_gro_requested(dev)) {
1326                 return veth_napi_enable_range(dev, start, end);
1327         }
1328         return 0;
1329 }
1330
1331 static void veth_set_xdp_features(struct net_device *dev)
1332 {
1333         struct veth_priv *priv = netdev_priv(dev);
1334         struct net_device *peer;
1335
1336         peer = rtnl_dereference(priv->peer);
1337         if (peer && peer->real_num_tx_queues <= dev->real_num_rx_queues) {
1338                 struct veth_priv *priv_peer = netdev_priv(peer);
1339                 xdp_features_t val = NETDEV_XDP_ACT_BASIC |
1340                                      NETDEV_XDP_ACT_REDIRECT |
1341                                      NETDEV_XDP_ACT_RX_SG;
1342
1343                 if (priv_peer->_xdp_prog || veth_gro_requested(peer))
1344                         val |= NETDEV_XDP_ACT_NDO_XMIT |
1345                                NETDEV_XDP_ACT_NDO_XMIT_SG;
1346                 xdp_set_features_flag(dev, val);
1347         } else {
1348                 xdp_clear_features_flag(dev);
1349         }
1350 }
1351
1352 static int veth_set_channels(struct net_device *dev,
1353                              struct ethtool_channels *ch)
1354 {
1355         struct veth_priv *priv = netdev_priv(dev);
1356         unsigned int old_rx_count, new_rx_count;
1357         struct veth_priv *peer_priv;
1358         struct net_device *peer;
1359         int err;
1360
1361         /* sanity check. Upper bounds are already enforced by the caller */
1362         if (!ch->rx_count || !ch->tx_count)
1363                 return -EINVAL;
1364
1365         /* avoid braking XDP, if that is enabled */
1366         peer = rtnl_dereference(priv->peer);
1367         peer_priv = peer ? netdev_priv(peer) : NULL;
1368         if (priv->_xdp_prog && peer && ch->rx_count < peer->real_num_tx_queues)
1369                 return -EINVAL;
1370
1371         if (peer && peer_priv && peer_priv->_xdp_prog && ch->tx_count > peer->real_num_rx_queues)
1372                 return -EINVAL;
1373
1374         old_rx_count = dev->real_num_rx_queues;
1375         new_rx_count = ch->rx_count;
1376         if (netif_running(dev)) {
1377                 /* turn device off */
1378                 netif_carrier_off(dev);
1379                 if (peer)
1380                         netif_carrier_off(peer);
1381
1382                 /* try to allocate new resurces, as needed*/
1383                 err = veth_enable_range_safe(dev, old_rx_count, new_rx_count);
1384                 if (err)
1385                         goto out;
1386         }
1387
1388         err = netif_set_real_num_rx_queues(dev, ch->rx_count);
1389         if (err)
1390                 goto revert;
1391
1392         err = netif_set_real_num_tx_queues(dev, ch->tx_count);
1393         if (err) {
1394                 int err2 = netif_set_real_num_rx_queues(dev, old_rx_count);
1395
1396                 /* this error condition could happen only if rx and tx change
1397                  * in opposite directions (e.g. tx nr raises, rx nr decreases)
1398                  * and we can't do anything to fully restore the original
1399                  * status
1400                  */
1401                 if (err2)
1402                         pr_warn("Can't restore rx queues config %d -> %d %d",
1403                                 new_rx_count, old_rx_count, err2);
1404                 else
1405                         goto revert;
1406         }
1407
1408 out:
1409         if (netif_running(dev)) {
1410                 /* note that we need to swap the arguments WRT the enable part
1411                  * to identify the range we have to disable
1412                  */
1413                 veth_disable_range_safe(dev, new_rx_count, old_rx_count);
1414                 netif_carrier_on(dev);
1415                 if (peer)
1416                         netif_carrier_on(peer);
1417         }
1418
1419         /* update XDP supported features */
1420         veth_set_xdp_features(dev);
1421         if (peer)
1422                 veth_set_xdp_features(peer);
1423
1424         return err;
1425
1426 revert:
1427         new_rx_count = old_rx_count;
1428         old_rx_count = ch->rx_count;
1429         goto out;
1430 }
1431
1432 static int veth_open(struct net_device *dev)
1433 {
1434         struct veth_priv *priv = netdev_priv(dev);
1435         struct net_device *peer = rtnl_dereference(priv->peer);
1436         int err;
1437
1438         if (!peer)
1439                 return -ENOTCONN;
1440
1441         if (priv->_xdp_prog) {
1442                 err = veth_enable_xdp(dev);
1443                 if (err)
1444                         return err;
1445         } else if (veth_gro_requested(dev)) {
1446                 err = veth_napi_enable(dev);
1447                 if (err)
1448                         return err;
1449         }
1450
1451         if (peer->flags & IFF_UP) {
1452                 netif_carrier_on(dev);
1453                 netif_carrier_on(peer);
1454         }
1455
1456         veth_set_xdp_features(dev);
1457
1458         return 0;
1459 }
1460
1461 static int veth_close(struct net_device *dev)
1462 {
1463         struct veth_priv *priv = netdev_priv(dev);
1464         struct net_device *peer = rtnl_dereference(priv->peer);
1465
1466         netif_carrier_off(dev);
1467         if (peer)
1468                 netif_carrier_off(peer);
1469
1470         if (priv->_xdp_prog)
1471                 veth_disable_xdp(dev);
1472         else if (veth_gro_requested(dev))
1473                 veth_napi_del(dev);
1474
1475         return 0;
1476 }
1477
1478 static int is_valid_veth_mtu(int mtu)
1479 {
1480         return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1481 }
1482
1483 static int veth_alloc_queues(struct net_device *dev)
1484 {
1485         struct veth_priv *priv = netdev_priv(dev);
1486         int i;
1487
1488         priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL_ACCOUNT);
1489         if (!priv->rq)
1490                 return -ENOMEM;
1491
1492         for (i = 0; i < dev->num_rx_queues; i++) {
1493                 priv->rq[i].dev = dev;
1494                 u64_stats_init(&priv->rq[i].stats.syncp);
1495         }
1496
1497         return 0;
1498 }
1499
1500 static void veth_free_queues(struct net_device *dev)
1501 {
1502         struct veth_priv *priv = netdev_priv(dev);
1503
1504         kfree(priv->rq);
1505 }
1506
1507 static int veth_dev_init(struct net_device *dev)
1508 {
1509         int err;
1510
1511         dev->lstats = netdev_alloc_pcpu_stats(struct pcpu_lstats);
1512         if (!dev->lstats)
1513                 return -ENOMEM;
1514
1515         err = veth_alloc_queues(dev);
1516         if (err) {
1517                 free_percpu(dev->lstats);
1518                 return err;
1519         }
1520
1521         return 0;
1522 }
1523
1524 static void veth_dev_free(struct net_device *dev)
1525 {
1526         veth_free_queues(dev);
1527         free_percpu(dev->lstats);
1528 }
1529
1530 #ifdef CONFIG_NET_POLL_CONTROLLER
1531 static void veth_poll_controller(struct net_device *dev)
1532 {
1533         /* veth only receives frames when its peer sends one
1534          * Since it has nothing to do with disabling irqs, we are guaranteed
1535          * never to have pending data when we poll for it so
1536          * there is nothing to do here.
1537          *
1538          * We need this though so netpoll recognizes us as an interface that
1539          * supports polling, which enables bridge devices in virt setups to
1540          * still use netconsole
1541          */
1542 }
1543 #endif  /* CONFIG_NET_POLL_CONTROLLER */
1544
1545 static int veth_get_iflink(const struct net_device *dev)
1546 {
1547         struct veth_priv *priv = netdev_priv(dev);
1548         struct net_device *peer;
1549         int iflink;
1550
1551         rcu_read_lock();
1552         peer = rcu_dereference(priv->peer);
1553         iflink = peer ? peer->ifindex : 0;
1554         rcu_read_unlock();
1555
1556         return iflink;
1557 }
1558
1559 static netdev_features_t veth_fix_features(struct net_device *dev,
1560                                            netdev_features_t features)
1561 {
1562         struct veth_priv *priv = netdev_priv(dev);
1563         struct net_device *peer;
1564
1565         peer = rtnl_dereference(priv->peer);
1566         if (peer) {
1567                 struct veth_priv *peer_priv = netdev_priv(peer);
1568
1569                 if (peer_priv->_xdp_prog)
1570                         features &= ~NETIF_F_GSO_SOFTWARE;
1571         }
1572         if (priv->_xdp_prog)
1573                 features |= NETIF_F_GRO;
1574
1575         return features;
1576 }
1577
1578 static int veth_set_features(struct net_device *dev,
1579                              netdev_features_t features)
1580 {
1581         netdev_features_t changed = features ^ dev->features;
1582         struct veth_priv *priv = netdev_priv(dev);
1583         struct net_device *peer;
1584         int err;
1585
1586         if (!(changed & NETIF_F_GRO) || !(dev->flags & IFF_UP) || priv->_xdp_prog)
1587                 return 0;
1588
1589         peer = rtnl_dereference(priv->peer);
1590         if (features & NETIF_F_GRO) {
1591                 err = veth_napi_enable(dev);
1592                 if (err)
1593                         return err;
1594
1595                 if (peer)
1596                         xdp_features_set_redirect_target(peer, true);
1597         } else {
1598                 if (peer)
1599                         xdp_features_clear_redirect_target(peer);
1600                 veth_napi_del(dev);
1601         }
1602         return 0;
1603 }
1604
1605 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1606 {
1607         struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1608         struct net_device *peer;
1609
1610         if (new_hr < 0)
1611                 new_hr = 0;
1612
1613         rcu_read_lock();
1614         peer = rcu_dereference(priv->peer);
1615         if (unlikely(!peer))
1616                 goto out;
1617
1618         peer_priv = netdev_priv(peer);
1619         priv->requested_headroom = new_hr;
1620         new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1621         dev->needed_headroom = new_hr;
1622         peer->needed_headroom = new_hr;
1623
1624 out:
1625         rcu_read_unlock();
1626 }
1627
1628 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1629                         struct netlink_ext_ack *extack)
1630 {
1631         struct veth_priv *priv = netdev_priv(dev);
1632         struct bpf_prog *old_prog;
1633         struct net_device *peer;
1634         unsigned int max_mtu;
1635         int err;
1636
1637         old_prog = priv->_xdp_prog;
1638         priv->_xdp_prog = prog;
1639         peer = rtnl_dereference(priv->peer);
1640
1641         if (prog) {
1642                 if (!peer) {
1643                         NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1644                         err = -ENOTCONN;
1645                         goto err;
1646                 }
1647
1648                 max_mtu = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) -
1649                           peer->hard_header_len;
1650                 /* Allow increasing the max_mtu if the program supports
1651                  * XDP fragments.
1652                  */
1653                 if (prog->aux->xdp_has_frags)
1654                         max_mtu += PAGE_SIZE * MAX_SKB_FRAGS;
1655
1656                 if (peer->mtu > max_mtu) {
1657                         NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1658                         err = -ERANGE;
1659                         goto err;
1660                 }
1661
1662                 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1663                         NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1664                         err = -ENOSPC;
1665                         goto err;
1666                 }
1667
1668                 if (dev->flags & IFF_UP) {
1669                         err = veth_enable_xdp(dev);
1670                         if (err) {
1671                                 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1672                                 goto err;
1673                         }
1674                 }
1675
1676                 if (!old_prog) {
1677                         peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1678                         peer->max_mtu = max_mtu;
1679                 }
1680
1681                 xdp_features_set_redirect_target(peer, true);
1682         }
1683
1684         if (old_prog) {
1685                 if (!prog) {
1686                         if (peer && !veth_gro_requested(dev))
1687                                 xdp_features_clear_redirect_target(peer);
1688
1689                         if (dev->flags & IFF_UP)
1690                                 veth_disable_xdp(dev);
1691
1692                         if (peer) {
1693                                 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1694                                 peer->max_mtu = ETH_MAX_MTU;
1695                         }
1696                 }
1697                 bpf_prog_put(old_prog);
1698         }
1699
1700         if ((!!old_prog ^ !!prog) && peer)
1701                 netdev_update_features(peer);
1702
1703         return 0;
1704 err:
1705         priv->_xdp_prog = old_prog;
1706
1707         return err;
1708 }
1709
1710 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1711 {
1712         switch (xdp->command) {
1713         case XDP_SETUP_PROG:
1714                 return veth_xdp_set(dev, xdp->prog, xdp->extack);
1715         default:
1716                 return -EINVAL;
1717         }
1718 }
1719
1720 static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
1721 {
1722         struct veth_xdp_buff *_ctx = (void *)ctx;
1723
1724         if (!_ctx->skb)
1725                 return -ENODATA;
1726
1727         *timestamp = skb_hwtstamps(_ctx->skb)->hwtstamp;
1728         return 0;
1729 }
1730
1731 static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
1732                             enum xdp_rss_hash_type *rss_type)
1733 {
1734         struct veth_xdp_buff *_ctx = (void *)ctx;
1735         struct sk_buff *skb = _ctx->skb;
1736
1737         if (!skb)
1738                 return -ENODATA;
1739
1740         *hash = skb_get_hash(skb);
1741         *rss_type = skb->l4_hash ? XDP_RSS_TYPE_L4_ANY : XDP_RSS_TYPE_NONE;
1742
1743         return 0;
1744 }
1745
1746 static const struct net_device_ops veth_netdev_ops = {
1747         .ndo_init            = veth_dev_init,
1748         .ndo_open            = veth_open,
1749         .ndo_stop            = veth_close,
1750         .ndo_start_xmit      = veth_xmit,
1751         .ndo_get_stats64     = veth_get_stats64,
1752         .ndo_set_rx_mode     = veth_set_multicast_list,
1753         .ndo_set_mac_address = eth_mac_addr,
1754 #ifdef CONFIG_NET_POLL_CONTROLLER
1755         .ndo_poll_controller    = veth_poll_controller,
1756 #endif
1757         .ndo_get_iflink         = veth_get_iflink,
1758         .ndo_fix_features       = veth_fix_features,
1759         .ndo_set_features       = veth_set_features,
1760         .ndo_features_check     = passthru_features_check,
1761         .ndo_set_rx_headroom    = veth_set_rx_headroom,
1762         .ndo_bpf                = veth_xdp,
1763         .ndo_xdp_xmit           = veth_ndo_xdp_xmit,
1764         .ndo_get_peer_dev       = veth_peer_dev,
1765 };
1766
1767 static const struct xdp_metadata_ops veth_xdp_metadata_ops = {
1768         .xmo_rx_timestamp               = veth_xdp_rx_timestamp,
1769         .xmo_rx_hash                    = veth_xdp_rx_hash,
1770 };
1771
1772 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1773                        NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1774                        NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1775                        NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1776                        NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1777
1778 static void veth_setup(struct net_device *dev)
1779 {
1780         ether_setup(dev);
1781
1782         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1783         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1784         dev->priv_flags |= IFF_NO_QUEUE;
1785         dev->priv_flags |= IFF_PHONY_HEADROOM;
1786
1787         dev->netdev_ops = &veth_netdev_ops;
1788         dev->xdp_metadata_ops = &veth_xdp_metadata_ops;
1789         dev->ethtool_ops = &veth_ethtool_ops;
1790         dev->features |= NETIF_F_LLTX;
1791         dev->features |= VETH_FEATURES;
1792         dev->vlan_features = dev->features &
1793                              ~(NETIF_F_HW_VLAN_CTAG_TX |
1794                                NETIF_F_HW_VLAN_STAG_TX |
1795                                NETIF_F_HW_VLAN_CTAG_RX |
1796                                NETIF_F_HW_VLAN_STAG_RX);
1797         dev->needs_free_netdev = true;
1798         dev->priv_destructor = veth_dev_free;
1799         dev->max_mtu = ETH_MAX_MTU;
1800
1801         dev->hw_features = VETH_FEATURES;
1802         dev->hw_enc_features = VETH_FEATURES;
1803         dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1804         netif_set_tso_max_size(dev, GSO_MAX_SIZE);
1805 }
1806
1807 /*
1808  * netlink interface
1809  */
1810
1811 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1812                          struct netlink_ext_ack *extack)
1813 {
1814         if (tb[IFLA_ADDRESS]) {
1815                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1816                         return -EINVAL;
1817                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1818                         return -EADDRNOTAVAIL;
1819         }
1820         if (tb[IFLA_MTU]) {
1821                 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1822                         return -EINVAL;
1823         }
1824         return 0;
1825 }
1826
1827 static struct rtnl_link_ops veth_link_ops;
1828
1829 static void veth_disable_gro(struct net_device *dev)
1830 {
1831         dev->features &= ~NETIF_F_GRO;
1832         dev->wanted_features &= ~NETIF_F_GRO;
1833         netdev_update_features(dev);
1834 }
1835
1836 static int veth_init_queues(struct net_device *dev, struct nlattr *tb[])
1837 {
1838         int err;
1839
1840         if (!tb[IFLA_NUM_TX_QUEUES] && dev->num_tx_queues > 1) {
1841                 err = netif_set_real_num_tx_queues(dev, 1);
1842                 if (err)
1843                         return err;
1844         }
1845         if (!tb[IFLA_NUM_RX_QUEUES] && dev->num_rx_queues > 1) {
1846                 err = netif_set_real_num_rx_queues(dev, 1);
1847                 if (err)
1848                         return err;
1849         }
1850         return 0;
1851 }
1852
1853 static int veth_newlink(struct net *src_net, struct net_device *dev,
1854                         struct nlattr *tb[], struct nlattr *data[],
1855                         struct netlink_ext_ack *extack)
1856 {
1857         int err;
1858         struct net_device *peer;
1859         struct veth_priv *priv;
1860         char ifname[IFNAMSIZ];
1861         struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1862         unsigned char name_assign_type;
1863         struct ifinfomsg *ifmp;
1864         struct net *net;
1865
1866         /*
1867          * create and register peer first
1868          */
1869         if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1870                 struct nlattr *nla_peer;
1871
1872                 nla_peer = data[VETH_INFO_PEER];
1873                 ifmp = nla_data(nla_peer);
1874                 err = rtnl_nla_parse_ifinfomsg(peer_tb, nla_peer, extack);
1875                 if (err < 0)
1876                         return err;
1877
1878                 err = veth_validate(peer_tb, NULL, extack);
1879                 if (err < 0)
1880                         return err;
1881
1882                 tbp = peer_tb;
1883         } else {
1884                 ifmp = NULL;
1885                 tbp = tb;
1886         }
1887
1888         if (ifmp && tbp[IFLA_IFNAME]) {
1889                 nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1890                 name_assign_type = NET_NAME_USER;
1891         } else {
1892                 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1893                 name_assign_type = NET_NAME_ENUM;
1894         }
1895
1896         net = rtnl_link_get_net(src_net, tbp);
1897         if (IS_ERR(net))
1898                 return PTR_ERR(net);
1899
1900         peer = rtnl_create_link(net, ifname, name_assign_type,
1901                                 &veth_link_ops, tbp, extack);
1902         if (IS_ERR(peer)) {
1903                 put_net(net);
1904                 return PTR_ERR(peer);
1905         }
1906
1907         if (!ifmp || !tbp[IFLA_ADDRESS])
1908                 eth_hw_addr_random(peer);
1909
1910         if (ifmp && (dev->ifindex != 0))
1911                 peer->ifindex = ifmp->ifi_index;
1912
1913         netif_inherit_tso_max(peer, dev);
1914
1915         err = register_netdevice(peer);
1916         put_net(net);
1917         net = NULL;
1918         if (err < 0)
1919                 goto err_register_peer;
1920
1921         /* keep GRO disabled by default to be consistent with the established
1922          * veth behavior
1923          */
1924         veth_disable_gro(peer);
1925         netif_carrier_off(peer);
1926
1927         err = rtnl_configure_link(peer, ifmp, 0, NULL);
1928         if (err < 0)
1929                 goto err_configure_peer;
1930
1931         /*
1932          * register dev last
1933          *
1934          * note, that since we've registered new device the dev's name
1935          * should be re-allocated
1936          */
1937
1938         if (tb[IFLA_ADDRESS] == NULL)
1939                 eth_hw_addr_random(dev);
1940
1941         if (tb[IFLA_IFNAME])
1942                 nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1943         else
1944                 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1945
1946         err = register_netdevice(dev);
1947         if (err < 0)
1948                 goto err_register_dev;
1949
1950         netif_carrier_off(dev);
1951
1952         /*
1953          * tie the deviced together
1954          */
1955
1956         priv = netdev_priv(dev);
1957         rcu_assign_pointer(priv->peer, peer);
1958         err = veth_init_queues(dev, tb);
1959         if (err)
1960                 goto err_queues;
1961
1962         priv = netdev_priv(peer);
1963         rcu_assign_pointer(priv->peer, dev);
1964         err = veth_init_queues(peer, tb);
1965         if (err)
1966                 goto err_queues;
1967
1968         veth_disable_gro(dev);
1969         /* update XDP supported features */
1970         veth_set_xdp_features(dev);
1971         veth_set_xdp_features(peer);
1972
1973         return 0;
1974
1975 err_queues:
1976         unregister_netdevice(dev);
1977 err_register_dev:
1978         /* nothing to do */
1979 err_configure_peer:
1980         unregister_netdevice(peer);
1981         return err;
1982
1983 err_register_peer:
1984         free_netdev(peer);
1985         return err;
1986 }
1987
1988 static void veth_dellink(struct net_device *dev, struct list_head *head)
1989 {
1990         struct veth_priv *priv;
1991         struct net_device *peer;
1992
1993         priv = netdev_priv(dev);
1994         peer = rtnl_dereference(priv->peer);
1995
1996         /* Note : dellink() is called from default_device_exit_batch(),
1997          * before a rcu_synchronize() point. The devices are guaranteed
1998          * not being freed before one RCU grace period.
1999          */
2000         RCU_INIT_POINTER(priv->peer, NULL);
2001         unregister_netdevice_queue(dev, head);
2002
2003         if (peer) {
2004                 priv = netdev_priv(peer);
2005                 RCU_INIT_POINTER(priv->peer, NULL);
2006                 unregister_netdevice_queue(peer, head);
2007         }
2008 }
2009
2010 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
2011         [VETH_INFO_PEER]        = { .len = sizeof(struct ifinfomsg) },
2012 };
2013
2014 static struct net *veth_get_link_net(const struct net_device *dev)
2015 {
2016         struct veth_priv *priv = netdev_priv(dev);
2017         struct net_device *peer = rtnl_dereference(priv->peer);
2018
2019         return peer ? dev_net(peer) : dev_net(dev);
2020 }
2021
2022 static unsigned int veth_get_num_queues(void)
2023 {
2024         /* enforce the same queue limit as rtnl_create_link */
2025         int queues = num_possible_cpus();
2026
2027         if (queues > 4096)
2028                 queues = 4096;
2029         return queues;
2030 }
2031
2032 static struct rtnl_link_ops veth_link_ops = {
2033         .kind           = DRV_NAME,
2034         .priv_size      = sizeof(struct veth_priv),
2035         .setup          = veth_setup,
2036         .validate       = veth_validate,
2037         .newlink        = veth_newlink,
2038         .dellink        = veth_dellink,
2039         .policy         = veth_policy,
2040         .maxtype        = VETH_INFO_MAX,
2041         .get_link_net   = veth_get_link_net,
2042         .get_num_tx_queues      = veth_get_num_queues,
2043         .get_num_rx_queues      = veth_get_num_queues,
2044 };
2045
2046 /*
2047  * init/fini
2048  */
2049
2050 static __init int veth_init(void)
2051 {
2052         return rtnl_link_register(&veth_link_ops);
2053 }
2054
2055 static __exit void veth_exit(void)
2056 {
2057         rtnl_link_unregister(&veth_link_ops);
2058 }
2059
2060 module_init(veth_init);
2061 module_exit(veth_exit);
2062
2063 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
2064 MODULE_LICENSE("GPL v2");
2065 MODULE_ALIAS_RTNL_LINK(DRV_NAME);