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         }
 240         pp_idx = idx + dev->real_num_tx_queues * VETH_TQ_STATS_LEN;
 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_sw_netstats_tx_add(dev, 1, 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 void veth_stats_rx(struct veth_stats *result, struct net_device *dev)
 391 {
 392         struct veth_priv *priv = netdev_priv(dev);
 393         int i;
 394
 395         result->peer_tq_xdp_xmit_err = 0;
 396         result->xdp_packets = 0;
 397         result->xdp_tx_err = 0;
 398         result->xdp_bytes = 0;
 399         result->rx_drops = 0;
 400         for (i = 0; i < dev->num_rx_queues; i++) {
 401                 u64 packets, bytes, drops, xdp_tx_err, peer_tq_xdp_xmit_err;
 402                 struct veth_rq_stats *stats = &priv->rq[i].stats;
 403                 unsigned int start;
 404
 405                 do {
 406                         start = u64_stats_fetch_begin(&stats->syncp);
 407                         peer_tq_xdp_xmit_err = stats->vs.peer_tq_xdp_xmit_err;
 408                         xdp_tx_err = stats->vs.xdp_tx_err;
 409                         packets = stats->vs.xdp_packets;
 410                         bytes = stats->vs.xdp_bytes;
 411                         drops = stats->vs.rx_drops;
 412                 } while (u64_stats_fetch_retry(&stats->syncp, start));
 413                 result->peer_tq_xdp_xmit_err += peer_tq_xdp_xmit_err;
 414                 result->xdp_tx_err += xdp_tx_err;
 415                 result->xdp_packets += packets;
 416                 result->xdp_bytes += bytes;
 417                 result->rx_drops += drops;
 418         }
 419 }
 420
 421 static void veth_get_stats64(struct net_device *dev,
 422                              struct rtnl_link_stats64 *tot)
 423 {
 424         struct veth_priv *priv = netdev_priv(dev);
 425         struct net_device *peer;
 426         struct veth_stats rx;
 427
 428         tot->tx_dropped = atomic64_read(&priv->dropped);
 429         dev_fetch_sw_netstats(tot, dev->tstats);
 430
 431         veth_stats_rx(&rx, dev);
 432         tot->tx_dropped += rx.xdp_tx_err;
 433         tot->rx_dropped = rx.rx_drops + rx.peer_tq_xdp_xmit_err;
 434         tot->rx_bytes += rx.xdp_bytes;
 435         tot->rx_packets += rx.xdp_packets;
 436
 437         rcu_read_lock();
 438         peer = rcu_dereference(priv->peer);
 439         if (peer) {
 440                 struct rtnl_link_stats64 tot_peer = {};
 441
 442                 dev_fetch_sw_netstats(&tot_peer, peer->tstats);
 443                 tot->rx_bytes += tot_peer.tx_bytes;
 444                 tot->rx_packets += tot_peer.tx_packets;
 445
 446                 veth_stats_rx(&rx, peer);
 447                 tot->tx_dropped += rx.peer_tq_xdp_xmit_err;
 448                 tot->rx_dropped += rx.xdp_tx_err;
 449                 tot->tx_bytes += rx.xdp_bytes;
 450                 tot->tx_packets += rx.xdp_packets;
 451         }
 452         rcu_read_unlock();
 453 }
 454
 455 /* fake multicast ability */
 456 static void veth_set_multicast_list(struct net_device *dev)
 457 {
 458 }
 459
 460 static int veth_select_rxq(struct net_device *dev)
 461 {
 462         return smp_processor_id() % dev->real_num_rx_queues;
 463 }
 464
 465 static struct net_device *veth_peer_dev(struct net_device *dev)
 466 {
 467         struct veth_priv *priv = netdev_priv(dev);
 468
 469         /* Callers must be under RCU read side. */
 470         return rcu_dereference(priv->peer);
 471 }
 472
 473 static int veth_xdp_xmit(struct net_device *dev, int n,
 474                          struct xdp_frame **frames,
 475                          u32 flags, bool ndo_xmit)
 476 {
 477         struct veth_priv *rcv_priv, *priv = netdev_priv(dev);
 478         int i, ret = -ENXIO, nxmit = 0;
 479         struct net_device *rcv;
 480         unsigned int max_len;
 481         struct veth_rq *rq;
 482
 483         if (unlikely(flags & ~XDP_XMIT_FLAGS_MASK))
 484                 return -EINVAL;
 485
 486         rcu_read_lock();
 487         rcv = rcu_dereference(priv->peer);
 488         if (unlikely(!rcv))
 489                 goto out;
 490
 491         rcv_priv = netdev_priv(rcv);
 492         rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 493         /* The napi pointer is set if NAPI is enabled, which ensures that
 494          * xdp_ring is initialized on receive side and the peer device is up.
 495          */
 496         if (!rcu_access_pointer(rq->napi))
 497                 goto out;
 498
 499         max_len = rcv->mtu + rcv->hard_header_len + VLAN_HLEN;
 500
 501         spin_lock(&rq->xdp_ring.producer_lock);
 502         for (i = 0; i < n; i++) {
 503                 struct xdp_frame *frame = frames[i];
 504                 void *ptr = veth_xdp_to_ptr(frame);
 505
 506                 if (unlikely(xdp_get_frame_len(frame) > max_len ||
 507                              __ptr_ring_produce(&rq->xdp_ring, ptr)))
 508                         break;
 509                 nxmit++;
 510         }
 511         spin_unlock(&rq->xdp_ring.producer_lock);
 512
 513         if (flags & XDP_XMIT_FLUSH)
 514                 __veth_xdp_flush(rq);
 515
 516         ret = nxmit;
 517         if (ndo_xmit) {
 518                 u64_stats_update_begin(&rq->stats.syncp);
 519                 rq->stats.vs.peer_tq_xdp_xmit += nxmit;
 520                 rq->stats.vs.peer_tq_xdp_xmit_err += n - nxmit;
 521                 u64_stats_update_end(&rq->stats.syncp);
 522         }
 523
 524 out:
 525         rcu_read_unlock();
 526
 527         return ret;
 528 }
 529
 530 static int veth_ndo_xdp_xmit(struct net_device *dev, int n,
 531                              struct xdp_frame **frames, u32 flags)
 532 {
 533         int err;
 534
 535         err = veth_xdp_xmit(dev, n, frames, flags, true);
 536         if (err < 0) {
 537                 struct veth_priv *priv = netdev_priv(dev);
 538
 539                 atomic64_add(n, &priv->dropped);
 540         }
 541
 542         return err;
 543 }
 544
 545 static void veth_xdp_flush_bq(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 546 {
 547         int sent, i, err = 0, drops;
 548
 549         sent = veth_xdp_xmit(rq->dev, bq->count, bq->q, 0, false);
 550         if (sent < 0) {
 551                 err = sent;
 552                 sent = 0;
 553         }
 554
 555         for (i = sent; unlikely(i < bq->count); i++)
 556                 xdp_return_frame(bq->q[i]);
 557
 558         drops = bq->count - sent;
 559         trace_xdp_bulk_tx(rq->dev, sent, drops, err);
 560
 561         u64_stats_update_begin(&rq->stats.syncp);
 562         rq->stats.vs.xdp_tx += sent;
 563         rq->stats.vs.xdp_tx_err += drops;
 564         u64_stats_update_end(&rq->stats.syncp);
 565
 566         bq->count = 0;
 567 }
 568
 569 static void veth_xdp_flush(struct veth_rq *rq, struct veth_xdp_tx_bq *bq)
 570 {
 571         struct veth_priv *rcv_priv, *priv = netdev_priv(rq->dev);
 572         struct net_device *rcv;
 573         struct veth_rq *rcv_rq;
 574
 575         rcu_read_lock();
 576         veth_xdp_flush_bq(rq, bq);
 577         rcv = rcu_dereference(priv->peer);
 578         if (unlikely(!rcv))
 579                 goto out;
 580
 581         rcv_priv = netdev_priv(rcv);
 582         rcv_rq = &rcv_priv->rq[veth_select_rxq(rcv)];
 583         /* xdp_ring is initialized on receive side? */
 584         if (unlikely(!rcu_access_pointer(rcv_rq->xdp_prog)))
 585                 goto out;
 586
 587         __veth_xdp_flush(rcv_rq);
 588 out:
 589         rcu_read_unlock();
 590 }
 591
 592 static int veth_xdp_tx(struct veth_rq *rq, struct xdp_buff *xdp,
 593                        struct veth_xdp_tx_bq *bq)
 594 {
 595         struct xdp_frame *frame = xdp_convert_buff_to_frame(xdp);
 596
 597         if (unlikely(!frame))
 598                 return -EOVERFLOW;
 599
 600         if (unlikely(bq->count == VETH_XDP_TX_BULK_SIZE))
 601                 veth_xdp_flush_bq(rq, bq);
 602
 603         bq->q[bq->count++] = frame;
 604
 605         return 0;
 606 }
 607
 608 static struct xdp_frame *veth_xdp_rcv_one(struct veth_rq *rq,
 609                                           struct xdp_frame *frame,
 610                                           struct veth_xdp_tx_bq *bq,
 611                                           struct veth_stats *stats)
 612 {
 613         struct xdp_frame orig_frame;
 614         struct bpf_prog *xdp_prog;
 615
 616         rcu_read_lock();
 617         xdp_prog = rcu_dereference(rq->xdp_prog);
 618         if (likely(xdp_prog)) {
 619                 struct veth_xdp_buff vxbuf;
 620                 struct xdp_buff *xdp = &vxbuf.xdp;
 621                 u32 act;
 622
 623                 xdp_convert_frame_to_buff(frame, xdp);
 624                 xdp->rxq = &rq->xdp_rxq;
 625                 vxbuf.skb = NULL;
 626
 627                 act = bpf_prog_run_xdp(xdp_prog, xdp);
 628
 629                 switch (act) {
 630                 case XDP_PASS:
 631                         if (xdp_update_frame_from_buff(xdp, frame))
 632                                 goto err_xdp;
 633                         break;
 634                 case XDP_TX:
 635                         orig_frame = *frame;
 636                         xdp->rxq->mem = frame->mem;
 637                         if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
 638                                 trace_xdp_exception(rq->dev, xdp_prog, act);
 639                                 frame = &orig_frame;
 640                                 stats->rx_drops++;
 641                                 goto err_xdp;
 642                         }
 643                         stats->xdp_tx++;
 644                         rcu_read_unlock();
 645                         goto xdp_xmit;
 646                 case XDP_REDIRECT:
 647                         orig_frame = *frame;
 648                         xdp->rxq->mem = frame->mem;
 649                         if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
 650                                 frame = &orig_frame;
 651                                 stats->rx_drops++;
 652                                 goto err_xdp;
 653                         }
 654                         stats->xdp_redirect++;
 655                         rcu_read_unlock();
 656                         goto xdp_xmit;
 657                 default:
 658                         bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 659                         fallthrough;
 660                 case XDP_ABORTED:
 661                         trace_xdp_exception(rq->dev, xdp_prog, act);
 662                         fallthrough;
 663                 case XDP_DROP:
 664                         stats->xdp_drops++;
 665                         goto err_xdp;
 666                 }
 667         }
 668         rcu_read_unlock();
 669
 670         return frame;
 671 err_xdp:
 672         rcu_read_unlock();
 673         xdp_return_frame(frame);
 674 xdp_xmit:
 675         return NULL;
 676 }
 677
 678 /* frames array contains VETH_XDP_BATCH at most */
 679 static void veth_xdp_rcv_bulk_skb(struct veth_rq *rq, void **frames,
 680                                   int n_xdpf, struct veth_xdp_tx_bq *bq,
 681                                   struct veth_stats *stats)
 682 {
 683         void *skbs[VETH_XDP_BATCH];
 684         int i;
 685
 686         if (xdp_alloc_skb_bulk(skbs, n_xdpf,
 687                                GFP_ATOMIC | __GFP_ZERO) < 0) {
 688                 for (i = 0; i < n_xdpf; i++)
 689                         xdp_return_frame(frames[i]);
 690                 stats->rx_drops += n_xdpf;
 691
 692                 return;
 693         }
 694
 695         for (i = 0; i < n_xdpf; i++) {
 696                 struct sk_buff *skb = skbs[i];
 697
 698                 skb = __xdp_build_skb_from_frame(frames[i], skb,
 699                                                  rq->dev);
 700                 if (!skb) {
 701                         xdp_return_frame(frames[i]);
 702                         stats->rx_drops++;
 703                         continue;
 704                 }
 705                 napi_gro_receive(&rq->xdp_napi, skb);
 706         }
 707 }
 708
 709 static void veth_xdp_get(struct xdp_buff *xdp)
 710 {
 711         struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp);
 712         int i;
 713
 714         get_page(virt_to_page(xdp->data));
 715         if (likely(!xdp_buff_has_frags(xdp)))
 716                 return;
 717
 718         for (i = 0; i < sinfo->nr_frags; i++)
 719                 __skb_frag_ref(&sinfo->frags[i]);
 720 }
 721
 722 static int veth_convert_skb_to_xdp_buff(struct veth_rq *rq,
 723                                         struct xdp_buff *xdp,
 724                                         struct sk_buff **pskb)
 725 {
 726         struct sk_buff *skb = *pskb;
 727         u32 frame_sz;
 728
 729         if (skb_shared(skb) || skb_head_is_locked(skb) ||
 730             skb_shinfo(skb)->nr_frags ||
 731             skb_headroom(skb) < XDP_PACKET_HEADROOM) {
 732                 if (skb_pp_cow_data(rq->page_pool, pskb, XDP_PACKET_HEADROOM))
 733                         goto drop;
 734
 735                 skb = *pskb;
 736         }
 737
 738         /* SKB "head" area always have tailroom for skb_shared_info */
 739         frame_sz = skb_end_pointer(skb) - skb->head;
 740         frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 741         xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq);
 742         xdp_prepare_buff(xdp, skb->head, skb_headroom(skb),
 743                          skb_headlen(skb), true);
 744
 745         if (skb_is_nonlinear(skb)) {
 746                 skb_shinfo(skb)->xdp_frags_size = skb->data_len;
 747                 xdp_buff_set_frags_flag(xdp);
 748         } else {
 749                 xdp_buff_clear_frags_flag(xdp);
 750         }
 751         *pskb = skb;
 752
 753         return 0;
 754 drop:
 755         consume_skb(skb);
 756         *pskb = NULL;
 757
 758         return -ENOMEM;
 759 }
 760
 761 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 762                                         struct sk_buff *skb,
 763                                         struct veth_xdp_tx_bq *bq,
 764                                         struct veth_stats *stats)
 765 {
 766         void *orig_data, *orig_data_end;
 767         struct bpf_prog *xdp_prog;
 768         struct veth_xdp_buff vxbuf;
 769         struct xdp_buff *xdp = &vxbuf.xdp;
 770         u32 act, metalen;
 771         int off;
 772
 773         skb_prepare_for_gro(skb);
 774
 775         rcu_read_lock();
 776         xdp_prog = rcu_dereference(rq->xdp_prog);
 777         if (unlikely(!xdp_prog)) {
 778                 rcu_read_unlock();
 779                 goto out;
 780         }
 781
 782         __skb_push(skb, skb->data - skb_mac_header(skb));
 783         if (veth_convert_skb_to_xdp_buff(rq, xdp, &skb))
 784                 goto drop;
 785         vxbuf.skb = skb;
 786
 787         orig_data = xdp->data;
 788         orig_data_end = xdp->data_end;
 789
 790         act = bpf_prog_run_xdp(xdp_prog, xdp);
 791
 792         switch (act) {
 793         case XDP_PASS:
 794                 break;
 795         case XDP_TX:
 796                 veth_xdp_get(xdp);
 797                 consume_skb(skb);
 798                 xdp->rxq->mem = rq->xdp_mem;
 799                 if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
 800                         trace_xdp_exception(rq->dev, xdp_prog, act);
 801                         stats->rx_drops++;
 802                         goto err_xdp;
 803                 }
 804                 stats->xdp_tx++;
 805                 rcu_read_unlock();
 806                 goto xdp_xmit;
 807         case XDP_REDIRECT:
 808                 veth_xdp_get(xdp);
 809                 consume_skb(skb);
 810                 xdp->rxq->mem = rq->xdp_mem;
 811                 if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
 812                         stats->rx_drops++;
 813                         goto err_xdp;
 814                 }
 815                 stats->xdp_redirect++;
 816                 rcu_read_unlock();
 817                 goto xdp_xmit;
 818         default:
 819                 bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 820                 fallthrough;
 821         case XDP_ABORTED:
 822                 trace_xdp_exception(rq->dev, xdp_prog, act);
 823                 fallthrough;
 824         case XDP_DROP:
 825                 stats->xdp_drops++;
 826                 goto xdp_drop;
 827         }
 828         rcu_read_unlock();
 829
 830         /* check if bpf_xdp_adjust_head was used */
 831         off = orig_data - xdp->data;
 832         if (off > 0)
 833                 __skb_push(skb, off);
 834         else if (off < 0)
 835                 __skb_pull(skb, -off);
 836
 837         skb_reset_mac_header(skb);
 838
 839         /* check if bpf_xdp_adjust_tail was used */
 840         off = xdp->data_end - orig_data_end;
 841         if (off != 0)
 842                 __skb_put(skb, off); /* positive on grow, negative on shrink */
 843
 844         /* XDP frag metadata (e.g. nr_frags) are updated in eBPF helpers
 845          * (e.g. bpf_xdp_adjust_tail), we need to update data_len here.
 846          */
 847         if (xdp_buff_has_frags(xdp))
 848                 skb->data_len = skb_shinfo(skb)->xdp_frags_size;
 849         else
 850                 skb->data_len = 0;
 851
 852         skb->protocol = eth_type_trans(skb, rq->dev);
 853
 854         metalen = xdp->data - xdp->data_meta;
 855         if (metalen)
 856                 skb_metadata_set(skb, metalen);
 857 out:
 858         return skb;
 859 drop:
 860         stats->rx_drops++;
 861 xdp_drop:
 862         rcu_read_unlock();
 863         kfree_skb(skb);
 864         return NULL;
 865 err_xdp:
 866         rcu_read_unlock();
 867         xdp_return_buff(xdp);
 868 xdp_xmit:
 869         return NULL;
 870 }
 871
 872 static int veth_xdp_rcv(struct veth_rq *rq, int budget,
 873                         struct veth_xdp_tx_bq *bq,
 874                         struct veth_stats *stats)
 875 {
 876         int i, done = 0, n_xdpf = 0;
 877         void *xdpf[VETH_XDP_BATCH];
 878
 879         for (i = 0; i < budget; i++) {
 880                 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
 881
 882                 if (!ptr)
 883                         break;
 884
 885                 if (veth_is_xdp_frame(ptr)) {
 886                         /* ndo_xdp_xmit */
 887                         struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
 888
 889                         stats->xdp_bytes += xdp_get_frame_len(frame);
 890                         frame = veth_xdp_rcv_one(rq, frame, bq, stats);
 891                         if (frame) {
 892                                 /* XDP_PASS */
 893                                 xdpf[n_xdpf++] = frame;
 894                                 if (n_xdpf == VETH_XDP_BATCH) {
 895                                         veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf,
 896                                                               bq, stats);
 897                                         n_xdpf = 0;
 898                                 }
 899                         }
 900                 } else {
 901                         /* ndo_start_xmit */
 902                         struct sk_buff *skb = ptr;
 903
 904                         stats->xdp_bytes += skb->len;
 905                         skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
 906                         if (skb) {
 907                                 if (skb_shared(skb) || skb_unclone(skb, GFP_ATOMIC))
 908                                         netif_receive_skb(skb);
 909                                 else
 910                                         napi_gro_receive(&rq->xdp_napi, skb);
 911                         }
 912                 }
 913                 done++;
 914         }
 915
 916         if (n_xdpf)
 917                 veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats);
 918
 919         u64_stats_update_begin(&rq->stats.syncp);
 920         rq->stats.vs.xdp_redirect += stats->xdp_redirect;
 921         rq->stats.vs.xdp_bytes += stats->xdp_bytes;
 922         rq->stats.vs.xdp_drops += stats->xdp_drops;
 923         rq->stats.vs.rx_drops += stats->rx_drops;
 924         rq->stats.vs.xdp_packets += done;
 925         u64_stats_update_end(&rq->stats.syncp);
 926
 927         return done;
 928 }
 929
 930 static int veth_poll(struct napi_struct *napi, int budget)
 931 {
 932         struct veth_rq *rq =
 933                 container_of(napi, struct veth_rq, xdp_napi);
 934         struct veth_stats stats = {};
 935         struct veth_xdp_tx_bq bq;
 936         int done;
 937
 938         bq.count = 0;
 939
 940         xdp_set_return_frame_no_direct();
 941         done = veth_xdp_rcv(rq, budget, &bq, &stats);
 942
 943         if (stats.xdp_redirect > 0)
 944                 xdp_do_flush();
 945
 946         if (done < budget && napi_complete_done(napi, done)) {
 947                 /* Write rx_notify_masked before reading ptr_ring */
 948                 smp_store_mb(rq->rx_notify_masked, false);
 949                 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
 950                         if (napi_schedule_prep(&rq->xdp_napi)) {
 951                                 WRITE_ONCE(rq->rx_notify_masked, true);
 952                                 __napi_schedule(&rq->xdp_napi);
 953                         }
 954                 }
 955         }
 956
 957         if (stats.xdp_tx > 0)
 958                 veth_xdp_flush(rq, &bq);
 959         xdp_clear_return_frame_no_direct();
 960
 961         return done;
 962 }
 963
 964 static int veth_create_page_pool(struct veth_rq *rq)
 965 {
 966         struct page_pool_params pp_params = {
 967                 .order = 0,
 968                 .pool_size = VETH_RING_SIZE,
 969                 .nid = NUMA_NO_NODE,
 970                 .dev = &rq->dev->dev,
 971         };
 972
 973         rq->page_pool = page_pool_create(&pp_params);
 974         if (IS_ERR(rq->page_pool)) {
 975                 int err = PTR_ERR(rq->page_pool);
 976
 977                 rq->page_pool = NULL;
 978                 return err;
 979         }
 980
 981         return 0;
 982 }
 983
 984 static int __veth_napi_enable_range(struct net_device *dev, int start, int end)
 985 {
 986         struct veth_priv *priv = netdev_priv(dev);
 987         int err, i;
 988
 989         for (i = start; i < end; i++) {
 990                 err = veth_create_page_pool(&priv->rq[i]);
 991                 if (err)
 992                         goto err_page_pool;
 993         }
 994
 995         for (i = start; i < end; i++) {
 996                 struct veth_rq *rq = &priv->rq[i];
 997
 998                 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
 999                 if (err)
1000                         goto err_xdp_ring;
1001         }
1002
1003         for (i = start; i < end; i++) {
1004                 struct veth_rq *rq = &priv->rq[i];
1005
1006                 napi_enable(&rq->xdp_napi);
1007                 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1008         }
1009
1010         return 0;
1011
1012 err_xdp_ring:
1013         for (i--; i >= start; i--)
1014                 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
1015         i = end;
1016 err_page_pool:
1017         for (i--; i >= start; i--) {
1018                 page_pool_destroy(priv->rq[i].page_pool);
1019                 priv->rq[i].page_pool = NULL;
1020         }
1021
1022         return err;
1023 }
1024
1025 static int __veth_napi_enable(struct net_device *dev)
1026 {
1027         return __veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1028 }
1029
1030 static void veth_napi_del_range(struct net_device *dev, int start, int end)
1031 {
1032         struct veth_priv *priv = netdev_priv(dev);
1033         int i;
1034
1035         for (i = start; i < end; i++) {
1036                 struct veth_rq *rq = &priv->rq[i];
1037
1038                 rcu_assign_pointer(priv->rq[i].napi, NULL);
1039                 napi_disable(&rq->xdp_napi);
1040                 __netif_napi_del(&rq->xdp_napi);
1041         }
1042         synchronize_net();
1043
1044         for (i = start; i < end; i++) {
1045                 struct veth_rq *rq = &priv->rq[i];
1046
1047                 rq->rx_notify_masked = false;
1048                 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
1049         }
1050
1051         for (i = start; i < end; i++) {
1052                 page_pool_destroy(priv->rq[i].page_pool);
1053                 priv->rq[i].page_pool = NULL;
1054         }
1055 }
1056
1057 static void veth_napi_del(struct net_device *dev)
1058 {
1059         veth_napi_del_range(dev, 0, dev->real_num_rx_queues);
1060 }
1061
1062 static bool veth_gro_requested(const struct net_device *dev)
1063 {
1064         return !!(dev->wanted_features & NETIF_F_GRO);
1065 }
1066
1067 static int veth_enable_xdp_range(struct net_device *dev, int start, int end,
1068                                  bool napi_already_on)
1069 {
1070         struct veth_priv *priv = netdev_priv(dev);
1071         int err, i;
1072
1073         for (i = start; i < end; i++) {
1074                 struct veth_rq *rq = &priv->rq[i];
1075
1076                 if (!napi_already_on)
1077                         netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1078                 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id);
1079                 if (err < 0)
1080                         goto err_rxq_reg;
1081
1082                 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
1083                                                  MEM_TYPE_PAGE_SHARED,
1084                                                  NULL);
1085                 if (err < 0)
1086                         goto err_reg_mem;
1087
1088                 /* Save original mem info as it can be overwritten */
1089                 rq->xdp_mem = rq->xdp_rxq.mem;
1090         }
1091         return 0;
1092
1093 err_reg_mem:
1094         xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
1095 err_rxq_reg:
1096         for (i--; i >= start; i--) {
1097                 struct veth_rq *rq = &priv->rq[i];
1098
1099                 xdp_rxq_info_unreg(&rq->xdp_rxq);
1100                 if (!napi_already_on)
1101                         netif_napi_del(&rq->xdp_napi);
1102         }
1103
1104         return err;
1105 }
1106
1107 static void veth_disable_xdp_range(struct net_device *dev, int start, int end,
1108                                    bool delete_napi)
1109 {
1110         struct veth_priv *priv = netdev_priv(dev);
1111         int i;
1112
1113         for (i = start; i < end; i++) {
1114                 struct veth_rq *rq = &priv->rq[i];
1115
1116                 rq->xdp_rxq.mem = rq->xdp_mem;
1117                 xdp_rxq_info_unreg(&rq->xdp_rxq);
1118
1119                 if (delete_napi)
1120                         netif_napi_del(&rq->xdp_napi);
1121         }
1122 }
1123
1124 static int veth_enable_xdp(struct net_device *dev)
1125 {
1126         bool napi_already_on = veth_gro_requested(dev) && (dev->flags & IFF_UP);
1127         struct veth_priv *priv = netdev_priv(dev);
1128         int err, i;
1129
1130         if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
1131                 err = veth_enable_xdp_range(dev, 0, dev->real_num_rx_queues, napi_already_on);
1132                 if (err)
1133                         return err;
1134
1135                 if (!napi_already_on) {
1136                         err = __veth_napi_enable(dev);
1137                         if (err) {
1138                                 veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, true);
1139                                 return err;
1140                         }
1141                 }
1142         }
1143
1144         for (i = 0; i < dev->real_num_rx_queues; i++) {
1145                 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
1146                 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1147         }
1148
1149         return 0;
1150 }
1151
1152 static void veth_disable_xdp(struct net_device *dev)
1153 {
1154         struct veth_priv *priv = netdev_priv(dev);
1155         int i;
1156
1157         for (i = 0; i < dev->real_num_rx_queues; i++)
1158                 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
1159
1160         if (!netif_running(dev) || !veth_gro_requested(dev))
1161                 veth_napi_del(dev);
1162
1163         veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, false);
1164 }
1165
1166 static int veth_napi_enable_range(struct net_device *dev, int start, int end)
1167 {
1168         struct veth_priv *priv = netdev_priv(dev);
1169         int err, i;
1170
1171         for (i = start; i < end; i++) {
1172                 struct veth_rq *rq = &priv->rq[i];
1173
1174                 netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1175         }
1176
1177         err = __veth_napi_enable_range(dev, start, end);
1178         if (err) {
1179                 for (i = start; i < end; i++) {
1180                         struct veth_rq *rq = &priv->rq[i];
1181
1182                         netif_napi_del(&rq->xdp_napi);
1183                 }
1184                 return err;
1185         }
1186         return err;
1187 }
1188
1189 static int veth_napi_enable(struct net_device *dev)
1190 {
1191         return veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1192 }
1193
1194 static void veth_disable_range_safe(struct net_device *dev, int start, int end)
1195 {
1196         struct veth_priv *priv = netdev_priv(dev);
1197
1198         if (start >= end)
1199                 return;
1200
1201         if (priv->_xdp_prog) {
1202                 veth_napi_del_range(dev, start, end);
1203                 veth_disable_xdp_range(dev, start, end, false);
1204         } else if (veth_gro_requested(dev)) {
1205                 veth_napi_del_range(dev, start, end);
1206         }
1207 }
1208
1209 static int veth_enable_range_safe(struct net_device *dev, int start, int end)
1210 {
1211         struct veth_priv *priv = netdev_priv(dev);
1212         int err;
1213
1214         if (start >= end)
1215                 return 0;
1216
1217         if (priv->_xdp_prog) {
1218                 /* these channels are freshly initialized, napi is not on there even
1219                  * when GRO is requeste
1220                  */
1221                 err = veth_enable_xdp_range(dev, start, end, false);
1222                 if (err)
1223                         return err;
1224
1225                 err = __veth_napi_enable_range(dev, start, end);
1226                 if (err) {
1227                         /* on error always delete the newly added napis */
1228                         veth_disable_xdp_range(dev, start, end, true);
1229                         return err;
1230                 }
1231         } else if (veth_gro_requested(dev)) {
1232                 return veth_napi_enable_range(dev, start, end);
1233         }
1234         return 0;
1235 }
1236
1237 static void veth_set_xdp_features(struct net_device *dev)
1238 {
1239         struct veth_priv *priv = netdev_priv(dev);
1240         struct net_device *peer;
1241
1242         peer = rtnl_dereference(priv->peer);
1243         if (peer && peer->real_num_tx_queues <= dev->real_num_rx_queues) {
1244                 struct veth_priv *priv_peer = netdev_priv(peer);
1245                 xdp_features_t val = NETDEV_XDP_ACT_BASIC |
1246                                      NETDEV_XDP_ACT_REDIRECT |
1247                                      NETDEV_XDP_ACT_RX_SG;
1248
1249                 if (priv_peer->_xdp_prog || veth_gro_requested(peer))
1250                         val |= NETDEV_XDP_ACT_NDO_XMIT |
1251                                NETDEV_XDP_ACT_NDO_XMIT_SG;
1252                 xdp_set_features_flag(dev, val);
1253         } else {
1254                 xdp_clear_features_flag(dev);
1255         }
1256 }
1257
1258 static int veth_set_channels(struct net_device *dev,
1259                              struct ethtool_channels *ch)
1260 {
1261         struct veth_priv *priv = netdev_priv(dev);
1262         unsigned int old_rx_count, new_rx_count;
1263         struct veth_priv *peer_priv;
1264         struct net_device *peer;
1265         int err;
1266
1267         /* sanity check. Upper bounds are already enforced by the caller */
1268         if (!ch->rx_count || !ch->tx_count)
1269                 return -EINVAL;
1270
1271         /* avoid braking XDP, if that is enabled */
1272         peer = rtnl_dereference(priv->peer);
1273         peer_priv = peer ? netdev_priv(peer) : NULL;
1274         if (priv->_xdp_prog && peer && ch->rx_count < peer->real_num_tx_queues)
1275                 return -EINVAL;
1276
1277         if (peer && peer_priv && peer_priv->_xdp_prog && ch->tx_count > peer->real_num_rx_queues)
1278                 return -EINVAL;
1279
1280         old_rx_count = dev->real_num_rx_queues;
1281         new_rx_count = ch->rx_count;
1282         if (netif_running(dev)) {
1283                 /* turn device off */
1284                 netif_carrier_off(dev);
1285                 if (peer)
1286                         netif_carrier_off(peer);
1287
1288                 /* try to allocate new resurces, as needed*/
1289                 err = veth_enable_range_safe(dev, old_rx_count, new_rx_count);
1290                 if (err)
1291                         goto out;
1292         }
1293
1294         err = netif_set_real_num_rx_queues(dev, ch->rx_count);
1295         if (err)
1296                 goto revert;
1297
1298         err = netif_set_real_num_tx_queues(dev, ch->tx_count);
1299         if (err) {
1300                 int err2 = netif_set_real_num_rx_queues(dev, old_rx_count);
1301
1302                 /* this error condition could happen only if rx and tx change
1303                  * in opposite directions (e.g. tx nr raises, rx nr decreases)
1304                  * and we can't do anything to fully restore the original
1305                  * status
1306                  */
1307                 if (err2)
1308                         pr_warn("Can't restore rx queues config %d -> %d %d",
1309                                 new_rx_count, old_rx_count, err2);
1310                 else
1311                         goto revert;
1312         }
1313
1314 out:
1315         if (netif_running(dev)) {
1316                 /* note that we need to swap the arguments WRT the enable part
1317                  * to identify the range we have to disable
1318                  */
1319                 veth_disable_range_safe(dev, new_rx_count, old_rx_count);
1320                 netif_carrier_on(dev);
1321                 if (peer)
1322                         netif_carrier_on(peer);
1323         }
1324
1325         /* update XDP supported features */
1326         veth_set_xdp_features(dev);
1327         if (peer)
1328                 veth_set_xdp_features(peer);
1329
1330         return err;
1331
1332 revert:
1333         new_rx_count = old_rx_count;
1334         old_rx_count = ch->rx_count;
1335         goto out;
1336 }
1337
1338 static int veth_open(struct net_device *dev)
1339 {
1340         struct veth_priv *priv = netdev_priv(dev);
1341         struct net_device *peer = rtnl_dereference(priv->peer);
1342         int err;
1343
1344         if (!peer)
1345                 return -ENOTCONN;
1346
1347         if (priv->_xdp_prog) {
1348                 err = veth_enable_xdp(dev);
1349                 if (err)
1350                         return err;
1351         } else if (veth_gro_requested(dev)) {
1352                 err = veth_napi_enable(dev);
1353                 if (err)
1354                         return err;
1355         }
1356
1357         if (peer->flags & IFF_UP) {
1358                 netif_carrier_on(dev);
1359                 netif_carrier_on(peer);
1360         }
1361
1362         veth_set_xdp_features(dev);
1363
1364         return 0;
1365 }
1366
1367 static int veth_close(struct net_device *dev)
1368 {
1369         struct veth_priv *priv = netdev_priv(dev);
1370         struct net_device *peer = rtnl_dereference(priv->peer);
1371
1372         netif_carrier_off(dev);
1373         if (peer)
1374                 netif_carrier_off(peer);
1375
1376         if (priv->_xdp_prog)
1377                 veth_disable_xdp(dev);
1378         else if (veth_gro_requested(dev))
1379                 veth_napi_del(dev);
1380
1381         return 0;
1382 }
1383
1384 static int is_valid_veth_mtu(int mtu)
1385 {
1386         return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1387 }
1388
1389 static int veth_alloc_queues(struct net_device *dev)
1390 {
1391         struct veth_priv *priv = netdev_priv(dev);
1392         int i;
1393
1394         priv->rq = kvcalloc(dev->num_rx_queues, sizeof(*priv->rq),
1395                             GFP_KERNEL_ACCOUNT | __GFP_RETRY_MAYFAIL);
1396         if (!priv->rq)
1397                 return -ENOMEM;
1398
1399         for (i = 0; i < dev->num_rx_queues; i++) {
1400                 priv->rq[i].dev = dev;
1401                 u64_stats_init(&priv->rq[i].stats.syncp);
1402         }
1403
1404         return 0;
1405 }
1406
1407 static void veth_free_queues(struct net_device *dev)
1408 {
1409         struct veth_priv *priv = netdev_priv(dev);
1410
1411         kvfree(priv->rq);
1412 }
1413
1414 static int veth_dev_init(struct net_device *dev)
1415 {
1416         netdev_lockdep_set_classes(dev);
1417         return veth_alloc_queues(dev);
1418 }
1419
1420 static void veth_dev_free(struct net_device *dev)
1421 {
1422         veth_free_queues(dev);
1423 }
1424
1425 #ifdef CONFIG_NET_POLL_CONTROLLER
1426 static void veth_poll_controller(struct net_device *dev)
1427 {
1428         /* veth only receives frames when its peer sends one
1429          * Since it has nothing to do with disabling irqs, we are guaranteed
1430          * never to have pending data when we poll for it so
1431          * there is nothing to do here.
1432          *
1433          * We need this though so netpoll recognizes us as an interface that
1434          * supports polling, which enables bridge devices in virt setups to
1435          * still use netconsole
1436          */
1437 }
1438 #endif  /* CONFIG_NET_POLL_CONTROLLER */
1439
1440 static int veth_get_iflink(const struct net_device *dev)
1441 {
1442         struct veth_priv *priv = netdev_priv(dev);
1443         struct net_device *peer;
1444         int iflink;
1445
1446         rcu_read_lock();
1447         peer = rcu_dereference(priv->peer);
1448         iflink = peer ? READ_ONCE(peer->ifindex) : 0;
1449         rcu_read_unlock();
1450
1451         return iflink;
1452 }
1453
1454 static netdev_features_t veth_fix_features(struct net_device *dev,
1455                                            netdev_features_t features)
1456 {
1457         struct veth_priv *priv = netdev_priv(dev);
1458         struct net_device *peer;
1459
1460         peer = rtnl_dereference(priv->peer);
1461         if (peer) {
1462                 struct veth_priv *peer_priv = netdev_priv(peer);
1463
1464                 if (peer_priv->_xdp_prog)
1465                         features &= ~NETIF_F_GSO_SOFTWARE;
1466         }
1467         if (priv->_xdp_prog)
1468                 features |= NETIF_F_GRO;
1469
1470         return features;
1471 }
1472
1473 static int veth_set_features(struct net_device *dev,
1474                              netdev_features_t features)
1475 {
1476         netdev_features_t changed = features ^ dev->features;
1477         struct veth_priv *priv = netdev_priv(dev);
1478         struct net_device *peer;
1479         int err;
1480
1481         if (!(changed & NETIF_F_GRO) || !(dev->flags & IFF_UP) || priv->_xdp_prog)
1482                 return 0;
1483
1484         peer = rtnl_dereference(priv->peer);
1485         if (features & NETIF_F_GRO) {
1486                 err = veth_napi_enable(dev);
1487                 if (err)
1488                         return err;
1489
1490                 if (peer)
1491                         xdp_features_set_redirect_target(peer, true);
1492         } else {
1493                 if (peer)
1494                         xdp_features_clear_redirect_target(peer);
1495                 veth_napi_del(dev);
1496         }
1497         return 0;
1498 }
1499
1500 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1501 {
1502         struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1503         struct net_device *peer;
1504
1505         if (new_hr < 0)
1506                 new_hr = 0;
1507
1508         rcu_read_lock();
1509         peer = rcu_dereference(priv->peer);
1510         if (unlikely(!peer))
1511                 goto out;
1512
1513         peer_priv = netdev_priv(peer);
1514         priv->requested_headroom = new_hr;
1515         new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1516         dev->needed_headroom = new_hr;
1517         peer->needed_headroom = new_hr;
1518
1519 out:
1520         rcu_read_unlock();
1521 }
1522
1523 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1524                         struct netlink_ext_ack *extack)
1525 {
1526         struct veth_priv *priv = netdev_priv(dev);
1527         struct bpf_prog *old_prog;
1528         struct net_device *peer;
1529         unsigned int max_mtu;
1530         int err;
1531
1532         old_prog = priv->_xdp_prog;
1533         priv->_xdp_prog = prog;
1534         peer = rtnl_dereference(priv->peer);
1535
1536         if (prog) {
1537                 if (!peer) {
1538                         NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1539                         err = -ENOTCONN;
1540                         goto err;
1541                 }
1542
1543                 max_mtu = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) -
1544                           peer->hard_header_len;
1545                 /* Allow increasing the max_mtu if the program supports
1546                  * XDP fragments.
1547                  */
1548                 if (prog->aux->xdp_has_frags)
1549                         max_mtu += PAGE_SIZE * MAX_SKB_FRAGS;
1550
1551                 if (peer->mtu > max_mtu) {
1552                         NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1553                         err = -ERANGE;
1554                         goto err;
1555                 }
1556
1557                 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1558                         NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1559                         err = -ENOSPC;
1560                         goto err;
1561                 }
1562
1563                 if (dev->flags & IFF_UP) {
1564                         err = veth_enable_xdp(dev);
1565                         if (err) {
1566                                 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1567                                 goto err;
1568                         }
1569                 }
1570
1571                 if (!old_prog) {
1572                         if (!veth_gro_requested(dev)) {
1573                                 /* user-space did not require GRO, but adding
1574                                  * XDP is supposed to get GRO working
1575                                  */
1576                                 dev->features |= NETIF_F_GRO;
1577                                 netdev_features_change(dev);
1578                         }
1579
1580                         peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1581                         peer->max_mtu = max_mtu;
1582                 }
1583
1584                 xdp_features_set_redirect_target(peer, true);
1585         }
1586
1587         if (old_prog) {
1588                 if (!prog) {
1589                         if (peer && !veth_gro_requested(dev))
1590                                 xdp_features_clear_redirect_target(peer);
1591
1592                         if (dev->flags & IFF_UP)
1593                                 veth_disable_xdp(dev);
1594
1595                         /* if user-space did not require GRO, since adding XDP
1596                          * enabled it, clear it now
1597                          */
1598                         if (!veth_gro_requested(dev)) {
1599                                 dev->features &= ~NETIF_F_GRO;
1600                                 netdev_features_change(dev);
1601                         }
1602
1603                         if (peer) {
1604                                 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1605                                 peer->max_mtu = ETH_MAX_MTU;
1606                         }
1607                 }
1608                 bpf_prog_put(old_prog);
1609         }
1610
1611         if ((!!old_prog ^ !!prog) && peer)
1612                 netdev_update_features(peer);
1613
1614         return 0;
1615 err:
1616         priv->_xdp_prog = old_prog;
1617
1618         return err;
1619 }
1620
1621 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1622 {
1623         switch (xdp->command) {
1624         case XDP_SETUP_PROG:
1625                 return veth_xdp_set(dev, xdp->prog, xdp->extack);
1626         default:
1627                 return -EINVAL;
1628         }
1629 }
1630
1631 static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
1632 {
1633         struct veth_xdp_buff *_ctx = (void *)ctx;
1634
1635         if (!_ctx->skb)
1636                 return -ENODATA;
1637
1638         *timestamp = skb_hwtstamps(_ctx->skb)->hwtstamp;
1639         return 0;
1640 }
1641
1642 static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
1643                             enum xdp_rss_hash_type *rss_type)
1644 {
1645         struct veth_xdp_buff *_ctx = (void *)ctx;
1646         struct sk_buff *skb = _ctx->skb;
1647
1648         if (!skb)
1649                 return -ENODATA;
1650
1651         *hash = skb_get_hash(skb);
1652         *rss_type = skb->l4_hash ? XDP_RSS_TYPE_L4_ANY : XDP_RSS_TYPE_NONE;
1653
1654         return 0;
1655 }
1656
1657 static int veth_xdp_rx_vlan_tag(const struct xdp_md *ctx, __be16 *vlan_proto,
1658                                 u16 *vlan_tci)
1659 {
1660         const struct veth_xdp_buff *_ctx = (void *)ctx;
1661         const struct sk_buff *skb = _ctx->skb;
1662         int err;
1663
1664         if (!skb)
1665                 return -ENODATA;
1666
1667         err = __vlan_hwaccel_get_tag(skb, vlan_tci);
1668         if (err)
1669                 return err;
1670
1671         *vlan_proto = skb->vlan_proto;
1672         return err;
1673 }
1674
1675 static const struct net_device_ops veth_netdev_ops = {
1676         .ndo_init            = veth_dev_init,
1677         .ndo_open            = veth_open,
1678         .ndo_stop            = veth_close,
1679         .ndo_start_xmit      = veth_xmit,
1680         .ndo_get_stats64     = veth_get_stats64,
1681         .ndo_set_rx_mode     = veth_set_multicast_list,
1682         .ndo_set_mac_address = eth_mac_addr,
1683 #ifdef CONFIG_NET_POLL_CONTROLLER
1684         .ndo_poll_controller    = veth_poll_controller,
1685 #endif
1686         .ndo_get_iflink         = veth_get_iflink,
1687         .ndo_fix_features       = veth_fix_features,
1688         .ndo_set_features       = veth_set_features,
1689         .ndo_features_check     = passthru_features_check,
1690         .ndo_set_rx_headroom    = veth_set_rx_headroom,
1691         .ndo_bpf                = veth_xdp,
1692         .ndo_xdp_xmit           = veth_ndo_xdp_xmit,
1693         .ndo_get_peer_dev       = veth_peer_dev,
1694 };
1695
1696 static const struct xdp_metadata_ops veth_xdp_metadata_ops = {
1697         .xmo_rx_timestamp               = veth_xdp_rx_timestamp,
1698         .xmo_rx_hash                    = veth_xdp_rx_hash,
1699         .xmo_rx_vlan_tag                = veth_xdp_rx_vlan_tag,
1700 };
1701
1702 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1703                        NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1704                        NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1705                        NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1706                        NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1707
1708 static void veth_setup(struct net_device *dev)
1709 {
1710         ether_setup(dev);
1711
1712         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1713         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1714         dev->priv_flags |= IFF_NO_QUEUE;
1715         dev->priv_flags |= IFF_PHONY_HEADROOM;
1716
1717         dev->netdev_ops = &veth_netdev_ops;
1718         dev->xdp_metadata_ops = &veth_xdp_metadata_ops;
1719         dev->ethtool_ops = &veth_ethtool_ops;
1720         dev->features |= NETIF_F_LLTX;
1721         dev->features |= VETH_FEATURES;
1722         dev->vlan_features = dev->features &
1723                              ~(NETIF_F_HW_VLAN_CTAG_TX |
1724                                NETIF_F_HW_VLAN_STAG_TX |
1725                                NETIF_F_HW_VLAN_CTAG_RX |
1726                                NETIF_F_HW_VLAN_STAG_RX);
1727         dev->needs_free_netdev = true;
1728         dev->priv_destructor = veth_dev_free;
1729         dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1730         dev->max_mtu = ETH_MAX_MTU;
1731
1732         dev->hw_features = VETH_FEATURES;
1733         dev->hw_enc_features = VETH_FEATURES;
1734         dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1735         netif_set_tso_max_size(dev, GSO_MAX_SIZE);
1736 }
1737
1738 /*
1739  * netlink interface
1740  */
1741
1742 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1743                          struct netlink_ext_ack *extack)
1744 {
1745         if (tb[IFLA_ADDRESS]) {
1746                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1747                         return -EINVAL;
1748                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1749                         return -EADDRNOTAVAIL;
1750         }
1751         if (tb[IFLA_MTU]) {
1752                 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1753                         return -EINVAL;
1754         }
1755         return 0;
1756 }
1757
1758 static struct rtnl_link_ops veth_link_ops;
1759
1760 static void veth_disable_gro(struct net_device *dev)
1761 {
1762         dev->features &= ~NETIF_F_GRO;
1763         dev->wanted_features &= ~NETIF_F_GRO;
1764         netdev_update_features(dev);
1765 }
1766
1767 static int veth_init_queues(struct net_device *dev, struct nlattr *tb[])
1768 {
1769         int err;
1770
1771         if (!tb[IFLA_NUM_TX_QUEUES] && dev->num_tx_queues > 1) {
1772                 err = netif_set_real_num_tx_queues(dev, 1);
1773                 if (err)
1774                         return err;
1775         }
1776         if (!tb[IFLA_NUM_RX_QUEUES] && dev->num_rx_queues > 1) {
1777                 err = netif_set_real_num_rx_queues(dev, 1);
1778                 if (err)
1779                         return err;
1780         }
1781         return 0;
1782 }
1783
1784 static int veth_newlink(struct net *src_net, struct net_device *dev,
1785                         struct nlattr *tb[], struct nlattr *data[],
1786                         struct netlink_ext_ack *extack)
1787 {
1788         int err;
1789         struct net_device *peer;
1790         struct veth_priv *priv;
1791         char ifname[IFNAMSIZ];
1792         struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1793         unsigned char name_assign_type;
1794         struct ifinfomsg *ifmp;
1795         struct net *net;
1796
1797         /*
1798          * create and register peer first
1799          */
1800         if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1801                 struct nlattr *nla_peer;
1802
1803                 nla_peer = data[VETH_INFO_PEER];
1804                 ifmp = nla_data(nla_peer);
1805                 err = rtnl_nla_parse_ifinfomsg(peer_tb, nla_peer, extack);
1806                 if (err < 0)
1807                         return err;
1808
1809                 err = veth_validate(peer_tb, NULL, extack);
1810                 if (err < 0)
1811                         return err;
1812
1813                 tbp = peer_tb;
1814         } else {
1815                 ifmp = NULL;
1816                 tbp = tb;
1817         }
1818
1819         if (ifmp && tbp[IFLA_IFNAME]) {
1820                 nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1821                 name_assign_type = NET_NAME_USER;
1822         } else {
1823                 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1824                 name_assign_type = NET_NAME_ENUM;
1825         }
1826
1827         net = rtnl_link_get_net(src_net, tbp);
1828         if (IS_ERR(net))
1829                 return PTR_ERR(net);
1830
1831         peer = rtnl_create_link(net, ifname, name_assign_type,
1832                                 &veth_link_ops, tbp, extack);
1833         if (IS_ERR(peer)) {
1834                 put_net(net);
1835                 return PTR_ERR(peer);
1836         }
1837
1838         if (!ifmp || !tbp[IFLA_ADDRESS])
1839                 eth_hw_addr_random(peer);
1840
1841         if (ifmp && (dev->ifindex != 0))
1842                 peer->ifindex = ifmp->ifi_index;
1843
1844         netif_inherit_tso_max(peer, dev);
1845
1846         err = register_netdevice(peer);
1847         put_net(net);
1848         net = NULL;
1849         if (err < 0)
1850                 goto err_register_peer;
1851
1852         /* keep GRO disabled by default to be consistent with the established
1853          * veth behavior
1854          */
1855         veth_disable_gro(peer);
1856         netif_carrier_off(peer);
1857
1858         err = rtnl_configure_link(peer, ifmp, 0, NULL);
1859         if (err < 0)
1860                 goto err_configure_peer;
1861
1862         /*
1863          * register dev last
1864          *
1865          * note, that since we've registered new device the dev's name
1866          * should be re-allocated
1867          */
1868
1869         if (tb[IFLA_ADDRESS] == NULL)
1870                 eth_hw_addr_random(dev);
1871
1872         if (tb[IFLA_IFNAME])
1873                 nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1874         else
1875                 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1876
1877         err = register_netdevice(dev);
1878         if (err < 0)
1879                 goto err_register_dev;
1880
1881         netif_carrier_off(dev);
1882
1883         /*
1884          * tie the deviced together
1885          */
1886
1887         priv = netdev_priv(dev);
1888         rcu_assign_pointer(priv->peer, peer);
1889         err = veth_init_queues(dev, tb);
1890         if (err)
1891                 goto err_queues;
1892
1893         priv = netdev_priv(peer);
1894         rcu_assign_pointer(priv->peer, dev);
1895         err = veth_init_queues(peer, tb);
1896         if (err)
1897                 goto err_queues;
1898
1899         veth_disable_gro(dev);
1900         /* update XDP supported features */
1901         veth_set_xdp_features(dev);
1902         veth_set_xdp_features(peer);
1903
1904         return 0;
1905
1906 err_queues:
1907         unregister_netdevice(dev);
1908 err_register_dev:
1909         /* nothing to do */
1910 err_configure_peer:
1911         unregister_netdevice(peer);
1912         return err;
1913
1914 err_register_peer:
1915         free_netdev(peer);
1916         return err;
1917 }
1918
1919 static void veth_dellink(struct net_device *dev, struct list_head *head)
1920 {
1921         struct veth_priv *priv;
1922         struct net_device *peer;
1923
1924         priv = netdev_priv(dev);
1925         peer = rtnl_dereference(priv->peer);
1926
1927         /* Note : dellink() is called from default_device_exit_batch(),
1928          * before a rcu_synchronize() point. The devices are guaranteed
1929          * not being freed before one RCU grace period.
1930          */
1931         RCU_INIT_POINTER(priv->peer, NULL);
1932         unregister_netdevice_queue(dev, head);
1933
1934         if (peer) {
1935                 priv = netdev_priv(peer);
1936                 RCU_INIT_POINTER(priv->peer, NULL);
1937                 unregister_netdevice_queue(peer, head);
1938         }
1939 }
1940
1941 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1942         [VETH_INFO_PEER]        = { .len = sizeof(struct ifinfomsg) },
1943 };
1944
1945 static struct net *veth_get_link_net(const struct net_device *dev)
1946 {
1947         struct veth_priv *priv = netdev_priv(dev);
1948         struct net_device *peer = rtnl_dereference(priv->peer);
1949
1950         return peer ? dev_net(peer) : dev_net(dev);
1951 }
1952
1953 static unsigned int veth_get_num_queues(void)
1954 {
1955         /* enforce the same queue limit as rtnl_create_link */
1956         int queues = num_possible_cpus();
1957
1958         if (queues > 4096)
1959                 queues = 4096;
1960         return queues;
1961 }
1962
1963 static struct rtnl_link_ops veth_link_ops = {
1964         .kind           = DRV_NAME,
1965         .priv_size      = sizeof(struct veth_priv),
1966         .setup          = veth_setup,
1967         .validate       = veth_validate,
1968         .newlink        = veth_newlink,
1969         .dellink        = veth_dellink,
1970         .policy         = veth_policy,
1971         .maxtype        = VETH_INFO_MAX,
1972         .get_link_net   = veth_get_link_net,
1973         .get_num_tx_queues      = veth_get_num_queues,
1974         .get_num_rx_queues      = veth_get_num_queues,
1975 };
1976
1977 /*
1978  * init/fini
1979  */
1980
1981 static __init int veth_init(void)
1982 {
1983         return rtnl_link_register(&veth_link_ops);
1984 }
1985
1986 static __exit void veth_exit(void)
1987 {
1988         rtnl_link_unregister(&veth_link_ops);
1989 }
1990
1991 module_init(veth_init);
1992 module_exit(veth_exit);
1993
1994 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
1995 MODULE_LICENSE("GPL v2");
1996 MODULE_ALIAS_RTNL_LINK(DRV_NAME);