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