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                 u32 size, len, max_head_size, off;
 733                 struct sk_buff *nskb;
 734                 struct page *page;
 735                 int i, head_off;
 736
 737                 /* We need a private copy of the skb and data buffers since
 738                  * the ebpf program can modify it. We segment the original skb
 739                  * into order-0 pages without linearize it.
 740                  *
 741                  * Make sure we have enough space for linear and paged area
 742                  */
 743                 max_head_size = SKB_WITH_OVERHEAD(PAGE_SIZE -
 744                                                   VETH_XDP_HEADROOM);
 745                 if (skb->len > PAGE_SIZE * MAX_SKB_FRAGS + max_head_size)
 746                         goto drop;
 747
 748                 /* Allocate skb head */
 749                 page = page_pool_dev_alloc_pages(rq->page_pool);
 750                 if (!page)
 751                         goto drop;
 752
 753                 nskb = napi_build_skb(page_address(page), PAGE_SIZE);
 754                 if (!nskb) {
 755                         page_pool_put_full_page(rq->page_pool, page, true);
 756                         goto drop;
 757                 }
 758
 759                 skb_reserve(nskb, VETH_XDP_HEADROOM);
 760                 skb_copy_header(nskb, skb);
 761                 skb_mark_for_recycle(nskb);
 762
 763                 size = min_t(u32, skb->len, max_head_size);
 764                 if (skb_copy_bits(skb, 0, nskb->data, size)) {
 765                         consume_skb(nskb);
 766                         goto drop;
 767                 }
 768                 skb_put(nskb, size);
 769
 770                 head_off = skb_headroom(nskb) - skb_headroom(skb);
 771                 skb_headers_offset_update(nskb, head_off);
 772
 773                 /* Allocate paged area of new skb */
 774                 off = size;
 775                 len = skb->len - off;
 776
 777                 for (i = 0; i < MAX_SKB_FRAGS && off < skb->len; i++) {
 778                         page = page_pool_dev_alloc_pages(rq->page_pool);
 779                         if (!page) {
 780                                 consume_skb(nskb);
 781                                 goto drop;
 782                         }
 783
 784                         size = min_t(u32, len, PAGE_SIZE);
 785                         skb_add_rx_frag(nskb, i, page, 0, size, PAGE_SIZE);
 786                         if (skb_copy_bits(skb, off, page_address(page),
 787                                           size)) {
 788                                 consume_skb(nskb);
 789                                 goto drop;
 790                         }
 791
 792                         len -= size;
 793                         off += size;
 794                 }
 795
 796                 consume_skb(skb);
 797                 skb = nskb;
 798         }
 799
 800         /* SKB "head" area always have tailroom for skb_shared_info */
 801         frame_sz = skb_end_pointer(skb) - skb->head;
 802         frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
 803         xdp_init_buff(xdp, frame_sz, &rq->xdp_rxq);
 804         xdp_prepare_buff(xdp, skb->head, skb_headroom(skb),
 805                          skb_headlen(skb), true);
 806
 807         if (skb_is_nonlinear(skb)) {
 808                 skb_shinfo(skb)->xdp_frags_size = skb->data_len;
 809                 xdp_buff_set_frags_flag(xdp);
 810         } else {
 811                 xdp_buff_clear_frags_flag(xdp);
 812         }
 813         *pskb = skb;
 814
 815         return 0;
 816 drop:
 817         consume_skb(skb);
 818         *pskb = NULL;
 819
 820         return -ENOMEM;
 821 }
 822
 823 static struct sk_buff *veth_xdp_rcv_skb(struct veth_rq *rq,
 824                                         struct sk_buff *skb,
 825                                         struct veth_xdp_tx_bq *bq,
 826                                         struct veth_stats *stats)
 827 {
 828         void *orig_data, *orig_data_end;
 829         struct bpf_prog *xdp_prog;
 830         struct veth_xdp_buff vxbuf;
 831         struct xdp_buff *xdp = &vxbuf.xdp;
 832         u32 act, metalen;
 833         int off;
 834
 835         skb_prepare_for_gro(skb);
 836
 837         rcu_read_lock();
 838         xdp_prog = rcu_dereference(rq->xdp_prog);
 839         if (unlikely(!xdp_prog)) {
 840                 rcu_read_unlock();
 841                 goto out;
 842         }
 843
 844         __skb_push(skb, skb->data - skb_mac_header(skb));
 845         if (veth_convert_skb_to_xdp_buff(rq, xdp, &skb))
 846                 goto drop;
 847         vxbuf.skb = skb;
 848
 849         orig_data = xdp->data;
 850         orig_data_end = xdp->data_end;
 851
 852         act = bpf_prog_run_xdp(xdp_prog, xdp);
 853
 854         switch (act) {
 855         case XDP_PASS:
 856                 break;
 857         case XDP_TX:
 858                 veth_xdp_get(xdp);
 859                 consume_skb(skb);
 860                 xdp->rxq->mem = rq->xdp_mem;
 861                 if (unlikely(veth_xdp_tx(rq, xdp, bq) < 0)) {
 862                         trace_xdp_exception(rq->dev, xdp_prog, act);
 863                         stats->rx_drops++;
 864                         goto err_xdp;
 865                 }
 866                 stats->xdp_tx++;
 867                 rcu_read_unlock();
 868                 goto xdp_xmit;
 869         case XDP_REDIRECT:
 870                 veth_xdp_get(xdp);
 871                 consume_skb(skb);
 872                 xdp->rxq->mem = rq->xdp_mem;
 873                 if (xdp_do_redirect(rq->dev, xdp, xdp_prog)) {
 874                         stats->rx_drops++;
 875                         goto err_xdp;
 876                 }
 877                 stats->xdp_redirect++;
 878                 rcu_read_unlock();
 879                 goto xdp_xmit;
 880         default:
 881                 bpf_warn_invalid_xdp_action(rq->dev, xdp_prog, act);
 882                 fallthrough;
 883         case XDP_ABORTED:
 884                 trace_xdp_exception(rq->dev, xdp_prog, act);
 885                 fallthrough;
 886         case XDP_DROP:
 887                 stats->xdp_drops++;
 888                 goto xdp_drop;
 889         }
 890         rcu_read_unlock();
 891
 892         /* check if bpf_xdp_adjust_head was used */
 893         off = orig_data - xdp->data;
 894         if (off > 0)
 895                 __skb_push(skb, off);
 896         else if (off < 0)
 897                 __skb_pull(skb, -off);
 898
 899         skb_reset_mac_header(skb);
 900
 901         /* check if bpf_xdp_adjust_tail was used */
 902         off = xdp->data_end - orig_data_end;
 903         if (off != 0)
 904                 __skb_put(skb, off); /* positive on grow, negative on shrink */
 905
 906         /* XDP frag metadata (e.g. nr_frags) are updated in eBPF helpers
 907          * (e.g. bpf_xdp_adjust_tail), we need to update data_len here.
 908          */
 909         if (xdp_buff_has_frags(xdp))
 910                 skb->data_len = skb_shinfo(skb)->xdp_frags_size;
 911         else
 912                 skb->data_len = 0;
 913
 914         skb->protocol = eth_type_trans(skb, rq->dev);
 915
 916         metalen = xdp->data - xdp->data_meta;
 917         if (metalen)
 918                 skb_metadata_set(skb, metalen);
 919 out:
 920         return skb;
 921 drop:
 922         stats->rx_drops++;
 923 xdp_drop:
 924         rcu_read_unlock();
 925         kfree_skb(skb);
 926         return NULL;
 927 err_xdp:
 928         rcu_read_unlock();
 929         xdp_return_buff(xdp);
 930 xdp_xmit:
 931         return NULL;
 932 }
 933
 934 static int veth_xdp_rcv(struct veth_rq *rq, int budget,
 935                         struct veth_xdp_tx_bq *bq,
 936                         struct veth_stats *stats)
 937 {
 938         int i, done = 0, n_xdpf = 0;
 939         void *xdpf[VETH_XDP_BATCH];
 940
 941         for (i = 0; i < budget; i++) {
 942                 void *ptr = __ptr_ring_consume(&rq->xdp_ring);
 943
 944                 if (!ptr)
 945                         break;
 946
 947                 if (veth_is_xdp_frame(ptr)) {
 948                         /* ndo_xdp_xmit */
 949                         struct xdp_frame *frame = veth_ptr_to_xdp(ptr);
 950
 951                         stats->xdp_bytes += xdp_get_frame_len(frame);
 952                         frame = veth_xdp_rcv_one(rq, frame, bq, stats);
 953                         if (frame) {
 954                                 /* XDP_PASS */
 955                                 xdpf[n_xdpf++] = frame;
 956                                 if (n_xdpf == VETH_XDP_BATCH) {
 957                                         veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf,
 958                                                               bq, stats);
 959                                         n_xdpf = 0;
 960                                 }
 961                         }
 962                 } else {
 963                         /* ndo_start_xmit */
 964                         struct sk_buff *skb = ptr;
 965
 966                         stats->xdp_bytes += skb->len;
 967                         skb = veth_xdp_rcv_skb(rq, skb, bq, stats);
 968                         if (skb) {
 969                                 if (skb_shared(skb) || skb_unclone(skb, GFP_ATOMIC))
 970                                         netif_receive_skb(skb);
 971                                 else
 972                                         napi_gro_receive(&rq->xdp_napi, skb);
 973                         }
 974                 }
 975                 done++;
 976         }
 977
 978         if (n_xdpf)
 979                 veth_xdp_rcv_bulk_skb(rq, xdpf, n_xdpf, bq, stats);
 980
 981         u64_stats_update_begin(&rq->stats.syncp);
 982         rq->stats.vs.xdp_redirect += stats->xdp_redirect;
 983         rq->stats.vs.xdp_bytes += stats->xdp_bytes;
 984         rq->stats.vs.xdp_drops += stats->xdp_drops;
 985         rq->stats.vs.rx_drops += stats->rx_drops;
 986         rq->stats.vs.xdp_packets += done;
 987         u64_stats_update_end(&rq->stats.syncp);
 988
 989         return done;
 990 }
 991
 992 static int veth_poll(struct napi_struct *napi, int budget)
 993 {
 994         struct veth_rq *rq =
 995                 container_of(napi, struct veth_rq, xdp_napi);
 996         struct veth_stats stats = {};
 997         struct veth_xdp_tx_bq bq;
 998         int done;
 999
1000         bq.count = 0;
1001
1002         xdp_set_return_frame_no_direct();
1003         done = veth_xdp_rcv(rq, budget, &bq, &stats);
1004
1005         if (stats.xdp_redirect > 0)
1006                 xdp_do_flush();
1007
1008         if (done < budget && napi_complete_done(napi, done)) {
1009                 /* Write rx_notify_masked before reading ptr_ring */
1010                 smp_store_mb(rq->rx_notify_masked, false);
1011                 if (unlikely(!__ptr_ring_empty(&rq->xdp_ring))) {
1012                         if (napi_schedule_prep(&rq->xdp_napi)) {
1013                                 WRITE_ONCE(rq->rx_notify_masked, true);
1014                                 __napi_schedule(&rq->xdp_napi);
1015                         }
1016                 }
1017         }
1018
1019         if (stats.xdp_tx > 0)
1020                 veth_xdp_flush(rq, &bq);
1021         xdp_clear_return_frame_no_direct();
1022
1023         return done;
1024 }
1025
1026 static int veth_create_page_pool(struct veth_rq *rq)
1027 {
1028         struct page_pool_params pp_params = {
1029                 .order = 0,
1030                 .pool_size = VETH_RING_SIZE,
1031                 .nid = NUMA_NO_NODE,
1032                 .dev = &rq->dev->dev,
1033         };
1034
1035         rq->page_pool = page_pool_create(&pp_params);
1036         if (IS_ERR(rq->page_pool)) {
1037                 int err = PTR_ERR(rq->page_pool);
1038
1039                 rq->page_pool = NULL;
1040                 return err;
1041         }
1042
1043         return 0;
1044 }
1045
1046 static int __veth_napi_enable_range(struct net_device *dev, int start, int end)
1047 {
1048         struct veth_priv *priv = netdev_priv(dev);
1049         int err, i;
1050
1051         for (i = start; i < end; i++) {
1052                 err = veth_create_page_pool(&priv->rq[i]);
1053                 if (err)
1054                         goto err_page_pool;
1055         }
1056
1057         for (i = start; i < end; i++) {
1058                 struct veth_rq *rq = &priv->rq[i];
1059
1060                 err = ptr_ring_init(&rq->xdp_ring, VETH_RING_SIZE, GFP_KERNEL);
1061                 if (err)
1062                         goto err_xdp_ring;
1063         }
1064
1065         for (i = start; i < end; i++) {
1066                 struct veth_rq *rq = &priv->rq[i];
1067
1068                 napi_enable(&rq->xdp_napi);
1069                 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1070         }
1071
1072         return 0;
1073
1074 err_xdp_ring:
1075         for (i--; i >= start; i--)
1076                 ptr_ring_cleanup(&priv->rq[i].xdp_ring, veth_ptr_free);
1077         i = end;
1078 err_page_pool:
1079         for (i--; i >= start; i--) {
1080                 page_pool_destroy(priv->rq[i].page_pool);
1081                 priv->rq[i].page_pool = NULL;
1082         }
1083
1084         return err;
1085 }
1086
1087 static int __veth_napi_enable(struct net_device *dev)
1088 {
1089         return __veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1090 }
1091
1092 static void veth_napi_del_range(struct net_device *dev, int start, int end)
1093 {
1094         struct veth_priv *priv = netdev_priv(dev);
1095         int i;
1096
1097         for (i = start; i < end; i++) {
1098                 struct veth_rq *rq = &priv->rq[i];
1099
1100                 rcu_assign_pointer(priv->rq[i].napi, NULL);
1101                 napi_disable(&rq->xdp_napi);
1102                 __netif_napi_del(&rq->xdp_napi);
1103         }
1104         synchronize_net();
1105
1106         for (i = start; i < end; i++) {
1107                 struct veth_rq *rq = &priv->rq[i];
1108
1109                 rq->rx_notify_masked = false;
1110                 ptr_ring_cleanup(&rq->xdp_ring, veth_ptr_free);
1111         }
1112
1113         for (i = start; i < end; i++) {
1114                 page_pool_destroy(priv->rq[i].page_pool);
1115                 priv->rq[i].page_pool = NULL;
1116         }
1117 }
1118
1119 static void veth_napi_del(struct net_device *dev)
1120 {
1121         veth_napi_del_range(dev, 0, dev->real_num_rx_queues);
1122 }
1123
1124 static bool veth_gro_requested(const struct net_device *dev)
1125 {
1126         return !!(dev->wanted_features & NETIF_F_GRO);
1127 }
1128
1129 static int veth_enable_xdp_range(struct net_device *dev, int start, int end,
1130                                  bool napi_already_on)
1131 {
1132         struct veth_priv *priv = netdev_priv(dev);
1133         int err, i;
1134
1135         for (i = start; i < end; i++) {
1136                 struct veth_rq *rq = &priv->rq[i];
1137
1138                 if (!napi_already_on)
1139                         netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1140                 err = xdp_rxq_info_reg(&rq->xdp_rxq, dev, i, rq->xdp_napi.napi_id);
1141                 if (err < 0)
1142                         goto err_rxq_reg;
1143
1144                 err = xdp_rxq_info_reg_mem_model(&rq->xdp_rxq,
1145                                                  MEM_TYPE_PAGE_SHARED,
1146                                                  NULL);
1147                 if (err < 0)
1148                         goto err_reg_mem;
1149
1150                 /* Save original mem info as it can be overwritten */
1151                 rq->xdp_mem = rq->xdp_rxq.mem;
1152         }
1153         return 0;
1154
1155 err_reg_mem:
1156         xdp_rxq_info_unreg(&priv->rq[i].xdp_rxq);
1157 err_rxq_reg:
1158         for (i--; i >= start; i--) {
1159                 struct veth_rq *rq = &priv->rq[i];
1160
1161                 xdp_rxq_info_unreg(&rq->xdp_rxq);
1162                 if (!napi_already_on)
1163                         netif_napi_del(&rq->xdp_napi);
1164         }
1165
1166         return err;
1167 }
1168
1169 static void veth_disable_xdp_range(struct net_device *dev, int start, int end,
1170                                    bool delete_napi)
1171 {
1172         struct veth_priv *priv = netdev_priv(dev);
1173         int i;
1174
1175         for (i = start; i < end; i++) {
1176                 struct veth_rq *rq = &priv->rq[i];
1177
1178                 rq->xdp_rxq.mem = rq->xdp_mem;
1179                 xdp_rxq_info_unreg(&rq->xdp_rxq);
1180
1181                 if (delete_napi)
1182                         netif_napi_del(&rq->xdp_napi);
1183         }
1184 }
1185
1186 static int veth_enable_xdp(struct net_device *dev)
1187 {
1188         bool napi_already_on = veth_gro_requested(dev) && (dev->flags & IFF_UP);
1189         struct veth_priv *priv = netdev_priv(dev);
1190         int err, i;
1191
1192         if (!xdp_rxq_info_is_reg(&priv->rq[0].xdp_rxq)) {
1193                 err = veth_enable_xdp_range(dev, 0, dev->real_num_rx_queues, napi_already_on);
1194                 if (err)
1195                         return err;
1196
1197                 if (!napi_already_on) {
1198                         err = __veth_napi_enable(dev);
1199                         if (err) {
1200                                 veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, true);
1201                                 return err;
1202                         }
1203
1204                         if (!veth_gro_requested(dev)) {
1205                                 /* user-space did not require GRO, but adding XDP
1206                                  * is supposed to get GRO working
1207                                  */
1208                                 dev->features |= NETIF_F_GRO;
1209                                 netdev_features_change(dev);
1210                         }
1211                 }
1212         }
1213
1214         for (i = 0; i < dev->real_num_rx_queues; i++) {
1215                 rcu_assign_pointer(priv->rq[i].xdp_prog, priv->_xdp_prog);
1216                 rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi);
1217         }
1218
1219         return 0;
1220 }
1221
1222 static void veth_disable_xdp(struct net_device *dev)
1223 {
1224         struct veth_priv *priv = netdev_priv(dev);
1225         int i;
1226
1227         for (i = 0; i < dev->real_num_rx_queues; i++)
1228                 rcu_assign_pointer(priv->rq[i].xdp_prog, NULL);
1229
1230         if (!netif_running(dev) || !veth_gro_requested(dev)) {
1231                 veth_napi_del(dev);
1232
1233                 /* if user-space did not require GRO, since adding XDP
1234                  * enabled it, clear it now
1235                  */
1236                 if (!veth_gro_requested(dev) && netif_running(dev)) {
1237                         dev->features &= ~NETIF_F_GRO;
1238                         netdev_features_change(dev);
1239                 }
1240         }
1241
1242         veth_disable_xdp_range(dev, 0, dev->real_num_rx_queues, false);
1243 }
1244
1245 static int veth_napi_enable_range(struct net_device *dev, int start, int end)
1246 {
1247         struct veth_priv *priv = netdev_priv(dev);
1248         int err, i;
1249
1250         for (i = start; i < end; i++) {
1251                 struct veth_rq *rq = &priv->rq[i];
1252
1253                 netif_napi_add(dev, &rq->xdp_napi, veth_poll);
1254         }
1255
1256         err = __veth_napi_enable_range(dev, start, end);
1257         if (err) {
1258                 for (i = start; i < end; i++) {
1259                         struct veth_rq *rq = &priv->rq[i];
1260
1261                         netif_napi_del(&rq->xdp_napi);
1262                 }
1263                 return err;
1264         }
1265         return err;
1266 }
1267
1268 static int veth_napi_enable(struct net_device *dev)
1269 {
1270         return veth_napi_enable_range(dev, 0, dev->real_num_rx_queues);
1271 }
1272
1273 static void veth_disable_range_safe(struct net_device *dev, int start, int end)
1274 {
1275         struct veth_priv *priv = netdev_priv(dev);
1276
1277         if (start >= end)
1278                 return;
1279
1280         if (priv->_xdp_prog) {
1281                 veth_napi_del_range(dev, start, end);
1282                 veth_disable_xdp_range(dev, start, end, false);
1283         } else if (veth_gro_requested(dev)) {
1284                 veth_napi_del_range(dev, start, end);
1285         }
1286 }
1287
1288 static int veth_enable_range_safe(struct net_device *dev, int start, int end)
1289 {
1290         struct veth_priv *priv = netdev_priv(dev);
1291         int err;
1292
1293         if (start >= end)
1294                 return 0;
1295
1296         if (priv->_xdp_prog) {
1297                 /* these channels are freshly initialized, napi is not on there even
1298                  * when GRO is requeste
1299                  */
1300                 err = veth_enable_xdp_range(dev, start, end, false);
1301                 if (err)
1302                         return err;
1303
1304                 err = __veth_napi_enable_range(dev, start, end);
1305                 if (err) {
1306                         /* on error always delete the newly added napis */
1307                         veth_disable_xdp_range(dev, start, end, true);
1308                         return err;
1309                 }
1310         } else if (veth_gro_requested(dev)) {
1311                 return veth_napi_enable_range(dev, start, end);
1312         }
1313         return 0;
1314 }
1315
1316 static void veth_set_xdp_features(struct net_device *dev)
1317 {
1318         struct veth_priv *priv = netdev_priv(dev);
1319         struct net_device *peer;
1320
1321         peer = rtnl_dereference(priv->peer);
1322         if (peer && peer->real_num_tx_queues <= dev->real_num_rx_queues) {
1323                 struct veth_priv *priv_peer = netdev_priv(peer);
1324                 xdp_features_t val = NETDEV_XDP_ACT_BASIC |
1325                                      NETDEV_XDP_ACT_REDIRECT |
1326                                      NETDEV_XDP_ACT_RX_SG;
1327
1328                 if (priv_peer->_xdp_prog || veth_gro_requested(peer))
1329                         val |= NETDEV_XDP_ACT_NDO_XMIT |
1330                                NETDEV_XDP_ACT_NDO_XMIT_SG;
1331                 xdp_set_features_flag(dev, val);
1332         } else {
1333                 xdp_clear_features_flag(dev);
1334         }
1335 }
1336
1337 static int veth_set_channels(struct net_device *dev,
1338                              struct ethtool_channels *ch)
1339 {
1340         struct veth_priv *priv = netdev_priv(dev);
1341         unsigned int old_rx_count, new_rx_count;
1342         struct veth_priv *peer_priv;
1343         struct net_device *peer;
1344         int err;
1345
1346         /* sanity check. Upper bounds are already enforced by the caller */
1347         if (!ch->rx_count || !ch->tx_count)
1348                 return -EINVAL;
1349
1350         /* avoid braking XDP, if that is enabled */
1351         peer = rtnl_dereference(priv->peer);
1352         peer_priv = peer ? netdev_priv(peer) : NULL;
1353         if (priv->_xdp_prog && peer && ch->rx_count < peer->real_num_tx_queues)
1354                 return -EINVAL;
1355
1356         if (peer && peer_priv && peer_priv->_xdp_prog && ch->tx_count > peer->real_num_rx_queues)
1357                 return -EINVAL;
1358
1359         old_rx_count = dev->real_num_rx_queues;
1360         new_rx_count = ch->rx_count;
1361         if (netif_running(dev)) {
1362                 /* turn device off */
1363                 netif_carrier_off(dev);
1364                 if (peer)
1365                         netif_carrier_off(peer);
1366
1367                 /* try to allocate new resurces, as needed*/
1368                 err = veth_enable_range_safe(dev, old_rx_count, new_rx_count);
1369                 if (err)
1370                         goto out;
1371         }
1372
1373         err = netif_set_real_num_rx_queues(dev, ch->rx_count);
1374         if (err)
1375                 goto revert;
1376
1377         err = netif_set_real_num_tx_queues(dev, ch->tx_count);
1378         if (err) {
1379                 int err2 = netif_set_real_num_rx_queues(dev, old_rx_count);
1380
1381                 /* this error condition could happen only if rx and tx change
1382                  * in opposite directions (e.g. tx nr raises, rx nr decreases)
1383                  * and we can't do anything to fully restore the original
1384                  * status
1385                  */
1386                 if (err2)
1387                         pr_warn("Can't restore rx queues config %d -> %d %d",
1388                                 new_rx_count, old_rx_count, err2);
1389                 else
1390                         goto revert;
1391         }
1392
1393 out:
1394         if (netif_running(dev)) {
1395                 /* note that we need to swap the arguments WRT the enable part
1396                  * to identify the range we have to disable
1397                  */
1398                 veth_disable_range_safe(dev, new_rx_count, old_rx_count);
1399                 netif_carrier_on(dev);
1400                 if (peer)
1401                         netif_carrier_on(peer);
1402         }
1403
1404         /* update XDP supported features */
1405         veth_set_xdp_features(dev);
1406         if (peer)
1407                 veth_set_xdp_features(peer);
1408
1409         return err;
1410
1411 revert:
1412         new_rx_count = old_rx_count;
1413         old_rx_count = ch->rx_count;
1414         goto out;
1415 }
1416
1417 static int veth_open(struct net_device *dev)
1418 {
1419         struct veth_priv *priv = netdev_priv(dev);
1420         struct net_device *peer = rtnl_dereference(priv->peer);
1421         int err;
1422
1423         if (!peer)
1424                 return -ENOTCONN;
1425
1426         if (priv->_xdp_prog) {
1427                 err = veth_enable_xdp(dev);
1428                 if (err)
1429                         return err;
1430         } else if (veth_gro_requested(dev)) {
1431                 err = veth_napi_enable(dev);
1432                 if (err)
1433                         return err;
1434         }
1435
1436         if (peer->flags & IFF_UP) {
1437                 netif_carrier_on(dev);
1438                 netif_carrier_on(peer);
1439         }
1440
1441         veth_set_xdp_features(dev);
1442
1443         return 0;
1444 }
1445
1446 static int veth_close(struct net_device *dev)
1447 {
1448         struct veth_priv *priv = netdev_priv(dev);
1449         struct net_device *peer = rtnl_dereference(priv->peer);
1450
1451         netif_carrier_off(dev);
1452         if (peer)
1453                 netif_carrier_off(peer);
1454
1455         if (priv->_xdp_prog)
1456                 veth_disable_xdp(dev);
1457         else if (veth_gro_requested(dev))
1458                 veth_napi_del(dev);
1459
1460         return 0;
1461 }
1462
1463 static int is_valid_veth_mtu(int mtu)
1464 {
1465         return mtu >= ETH_MIN_MTU && mtu <= ETH_MAX_MTU;
1466 }
1467
1468 static int veth_alloc_queues(struct net_device *dev)
1469 {
1470         struct veth_priv *priv = netdev_priv(dev);
1471         int i;
1472
1473         priv->rq = kcalloc(dev->num_rx_queues, sizeof(*priv->rq), GFP_KERNEL_ACCOUNT);
1474         if (!priv->rq)
1475                 return -ENOMEM;
1476
1477         for (i = 0; i < dev->num_rx_queues; i++) {
1478                 priv->rq[i].dev = dev;
1479                 u64_stats_init(&priv->rq[i].stats.syncp);
1480         }
1481
1482         return 0;
1483 }
1484
1485 static void veth_free_queues(struct net_device *dev)
1486 {
1487         struct veth_priv *priv = netdev_priv(dev);
1488
1489         kfree(priv->rq);
1490 }
1491
1492 static int veth_dev_init(struct net_device *dev)
1493 {
1494         return veth_alloc_queues(dev);
1495 }
1496
1497 static void veth_dev_free(struct net_device *dev)
1498 {
1499         veth_free_queues(dev);
1500 }
1501
1502 #ifdef CONFIG_NET_POLL_CONTROLLER
1503 static void veth_poll_controller(struct net_device *dev)
1504 {
1505         /* veth only receives frames when its peer sends one
1506          * Since it has nothing to do with disabling irqs, we are guaranteed
1507          * never to have pending data when we poll for it so
1508          * there is nothing to do here.
1509          *
1510          * We need this though so netpoll recognizes us as an interface that
1511          * supports polling, which enables bridge devices in virt setups to
1512          * still use netconsole
1513          */
1514 }
1515 #endif  /* CONFIG_NET_POLL_CONTROLLER */
1516
1517 static int veth_get_iflink(const struct net_device *dev)
1518 {
1519         struct veth_priv *priv = netdev_priv(dev);
1520         struct net_device *peer;
1521         int iflink;
1522
1523         rcu_read_lock();
1524         peer = rcu_dereference(priv->peer);
1525         iflink = peer ? peer->ifindex : 0;
1526         rcu_read_unlock();
1527
1528         return iflink;
1529 }
1530
1531 static netdev_features_t veth_fix_features(struct net_device *dev,
1532                                            netdev_features_t features)
1533 {
1534         struct veth_priv *priv = netdev_priv(dev);
1535         struct net_device *peer;
1536
1537         peer = rtnl_dereference(priv->peer);
1538         if (peer) {
1539                 struct veth_priv *peer_priv = netdev_priv(peer);
1540
1541                 if (peer_priv->_xdp_prog)
1542                         features &= ~NETIF_F_GSO_SOFTWARE;
1543         }
1544         if (priv->_xdp_prog)
1545                 features |= NETIF_F_GRO;
1546
1547         return features;
1548 }
1549
1550 static int veth_set_features(struct net_device *dev,
1551                              netdev_features_t features)
1552 {
1553         netdev_features_t changed = features ^ dev->features;
1554         struct veth_priv *priv = netdev_priv(dev);
1555         struct net_device *peer;
1556         int err;
1557
1558         if (!(changed & NETIF_F_GRO) || !(dev->flags & IFF_UP) || priv->_xdp_prog)
1559                 return 0;
1560
1561         peer = rtnl_dereference(priv->peer);
1562         if (features & NETIF_F_GRO) {
1563                 err = veth_napi_enable(dev);
1564                 if (err)
1565                         return err;
1566
1567                 if (peer)
1568                         xdp_features_set_redirect_target(peer, true);
1569         } else {
1570                 if (peer)
1571                         xdp_features_clear_redirect_target(peer);
1572                 veth_napi_del(dev);
1573         }
1574         return 0;
1575 }
1576
1577 static void veth_set_rx_headroom(struct net_device *dev, int new_hr)
1578 {
1579         struct veth_priv *peer_priv, *priv = netdev_priv(dev);
1580         struct net_device *peer;
1581
1582         if (new_hr < 0)
1583                 new_hr = 0;
1584
1585         rcu_read_lock();
1586         peer = rcu_dereference(priv->peer);
1587         if (unlikely(!peer))
1588                 goto out;
1589
1590         peer_priv = netdev_priv(peer);
1591         priv->requested_headroom = new_hr;
1592         new_hr = max(priv->requested_headroom, peer_priv->requested_headroom);
1593         dev->needed_headroom = new_hr;
1594         peer->needed_headroom = new_hr;
1595
1596 out:
1597         rcu_read_unlock();
1598 }
1599
1600 static int veth_xdp_set(struct net_device *dev, struct bpf_prog *prog,
1601                         struct netlink_ext_ack *extack)
1602 {
1603         struct veth_priv *priv = netdev_priv(dev);
1604         struct bpf_prog *old_prog;
1605         struct net_device *peer;
1606         unsigned int max_mtu;
1607         int err;
1608
1609         old_prog = priv->_xdp_prog;
1610         priv->_xdp_prog = prog;
1611         peer = rtnl_dereference(priv->peer);
1612
1613         if (prog) {
1614                 if (!peer) {
1615                         NL_SET_ERR_MSG_MOD(extack, "Cannot set XDP when peer is detached");
1616                         err = -ENOTCONN;
1617                         goto err;
1618                 }
1619
1620                 max_mtu = SKB_WITH_OVERHEAD(PAGE_SIZE - VETH_XDP_HEADROOM) -
1621                           peer->hard_header_len;
1622                 /* Allow increasing the max_mtu if the program supports
1623                  * XDP fragments.
1624                  */
1625                 if (prog->aux->xdp_has_frags)
1626                         max_mtu += PAGE_SIZE * MAX_SKB_FRAGS;
1627
1628                 if (peer->mtu > max_mtu) {
1629                         NL_SET_ERR_MSG_MOD(extack, "Peer MTU is too large to set XDP");
1630                         err = -ERANGE;
1631                         goto err;
1632                 }
1633
1634                 if (dev->real_num_rx_queues < peer->real_num_tx_queues) {
1635                         NL_SET_ERR_MSG_MOD(extack, "XDP expects number of rx queues not less than peer tx queues");
1636                         err = -ENOSPC;
1637                         goto err;
1638                 }
1639
1640                 if (dev->flags & IFF_UP) {
1641                         err = veth_enable_xdp(dev);
1642                         if (err) {
1643                                 NL_SET_ERR_MSG_MOD(extack, "Setup for XDP failed");
1644                                 goto err;
1645                         }
1646                 }
1647
1648                 if (!old_prog) {
1649                         peer->hw_features &= ~NETIF_F_GSO_SOFTWARE;
1650                         peer->max_mtu = max_mtu;
1651                 }
1652
1653                 xdp_features_set_redirect_target(peer, true);
1654         }
1655
1656         if (old_prog) {
1657                 if (!prog) {
1658                         if (peer && !veth_gro_requested(dev))
1659                                 xdp_features_clear_redirect_target(peer);
1660
1661                         if (dev->flags & IFF_UP)
1662                                 veth_disable_xdp(dev);
1663
1664                         if (peer) {
1665                                 peer->hw_features |= NETIF_F_GSO_SOFTWARE;
1666                                 peer->max_mtu = ETH_MAX_MTU;
1667                         }
1668                 }
1669                 bpf_prog_put(old_prog);
1670         }
1671
1672         if ((!!old_prog ^ !!prog) && peer)
1673                 netdev_update_features(peer);
1674
1675         return 0;
1676 err:
1677         priv->_xdp_prog = old_prog;
1678
1679         return err;
1680 }
1681
1682 static int veth_xdp(struct net_device *dev, struct netdev_bpf *xdp)
1683 {
1684         switch (xdp->command) {
1685         case XDP_SETUP_PROG:
1686                 return veth_xdp_set(dev, xdp->prog, xdp->extack);
1687         default:
1688                 return -EINVAL;
1689         }
1690 }
1691
1692 static int veth_xdp_rx_timestamp(const struct xdp_md *ctx, u64 *timestamp)
1693 {
1694         struct veth_xdp_buff *_ctx = (void *)ctx;
1695
1696         if (!_ctx->skb)
1697                 return -ENODATA;
1698
1699         *timestamp = skb_hwtstamps(_ctx->skb)->hwtstamp;
1700         return 0;
1701 }
1702
1703 static int veth_xdp_rx_hash(const struct xdp_md *ctx, u32 *hash,
1704                             enum xdp_rss_hash_type *rss_type)
1705 {
1706         struct veth_xdp_buff *_ctx = (void *)ctx;
1707         struct sk_buff *skb = _ctx->skb;
1708
1709         if (!skb)
1710                 return -ENODATA;
1711
1712         *hash = skb_get_hash(skb);
1713         *rss_type = skb->l4_hash ? XDP_RSS_TYPE_L4_ANY : XDP_RSS_TYPE_NONE;
1714
1715         return 0;
1716 }
1717
1718 static const struct net_device_ops veth_netdev_ops = {
1719         .ndo_init            = veth_dev_init,
1720         .ndo_open            = veth_open,
1721         .ndo_stop            = veth_close,
1722         .ndo_start_xmit      = veth_xmit,
1723         .ndo_get_stats64     = veth_get_stats64,
1724         .ndo_set_rx_mode     = veth_set_multicast_list,
1725         .ndo_set_mac_address = eth_mac_addr,
1726 #ifdef CONFIG_NET_POLL_CONTROLLER
1727         .ndo_poll_controller    = veth_poll_controller,
1728 #endif
1729         .ndo_get_iflink         = veth_get_iflink,
1730         .ndo_fix_features       = veth_fix_features,
1731         .ndo_set_features       = veth_set_features,
1732         .ndo_features_check     = passthru_features_check,
1733         .ndo_set_rx_headroom    = veth_set_rx_headroom,
1734         .ndo_bpf                = veth_xdp,
1735         .ndo_xdp_xmit           = veth_ndo_xdp_xmit,
1736         .ndo_get_peer_dev       = veth_peer_dev,
1737 };
1738
1739 static const struct xdp_metadata_ops veth_xdp_metadata_ops = {
1740         .xmo_rx_timestamp               = veth_xdp_rx_timestamp,
1741         .xmo_rx_hash                    = veth_xdp_rx_hash,
1742 };
1743
1744 #define VETH_FEATURES (NETIF_F_SG | NETIF_F_FRAGLIST | NETIF_F_HW_CSUM | \
1745                        NETIF_F_RXCSUM | NETIF_F_SCTP_CRC | NETIF_F_HIGHDMA | \
1746                        NETIF_F_GSO_SOFTWARE | NETIF_F_GSO_ENCAP_ALL | \
1747                        NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_CTAG_RX | \
1748                        NETIF_F_HW_VLAN_STAG_TX | NETIF_F_HW_VLAN_STAG_RX )
1749
1750 static void veth_setup(struct net_device *dev)
1751 {
1752         ether_setup(dev);
1753
1754         dev->priv_flags &= ~IFF_TX_SKB_SHARING;
1755         dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
1756         dev->priv_flags |= IFF_NO_QUEUE;
1757         dev->priv_flags |= IFF_PHONY_HEADROOM;
1758
1759         dev->netdev_ops = &veth_netdev_ops;
1760         dev->xdp_metadata_ops = &veth_xdp_metadata_ops;
1761         dev->ethtool_ops = &veth_ethtool_ops;
1762         dev->features |= NETIF_F_LLTX;
1763         dev->features |= VETH_FEATURES;
1764         dev->vlan_features = dev->features &
1765                              ~(NETIF_F_HW_VLAN_CTAG_TX |
1766                                NETIF_F_HW_VLAN_STAG_TX |
1767                                NETIF_F_HW_VLAN_CTAG_RX |
1768                                NETIF_F_HW_VLAN_STAG_RX);
1769         dev->needs_free_netdev = true;
1770         dev->priv_destructor = veth_dev_free;
1771         dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1772         dev->max_mtu = ETH_MAX_MTU;
1773
1774         dev->hw_features = VETH_FEATURES;
1775         dev->hw_enc_features = VETH_FEATURES;
1776         dev->mpls_features = NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE;
1777         netif_set_tso_max_size(dev, GSO_MAX_SIZE);
1778 }
1779
1780 /*
1781  * netlink interface
1782  */
1783
1784 static int veth_validate(struct nlattr *tb[], struct nlattr *data[],
1785                          struct netlink_ext_ack *extack)
1786 {
1787         if (tb[IFLA_ADDRESS]) {
1788                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
1789                         return -EINVAL;
1790                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
1791                         return -EADDRNOTAVAIL;
1792         }
1793         if (tb[IFLA_MTU]) {
1794                 if (!is_valid_veth_mtu(nla_get_u32(tb[IFLA_MTU])))
1795                         return -EINVAL;
1796         }
1797         return 0;
1798 }
1799
1800 static struct rtnl_link_ops veth_link_ops;
1801
1802 static void veth_disable_gro(struct net_device *dev)
1803 {
1804         dev->features &= ~NETIF_F_GRO;
1805         dev->wanted_features &= ~NETIF_F_GRO;
1806         netdev_update_features(dev);
1807 }
1808
1809 static int veth_init_queues(struct net_device *dev, struct nlattr *tb[])
1810 {
1811         int err;
1812
1813         if (!tb[IFLA_NUM_TX_QUEUES] && dev->num_tx_queues > 1) {
1814                 err = netif_set_real_num_tx_queues(dev, 1);
1815                 if (err)
1816                         return err;
1817         }
1818         if (!tb[IFLA_NUM_RX_QUEUES] && dev->num_rx_queues > 1) {
1819                 err = netif_set_real_num_rx_queues(dev, 1);
1820                 if (err)
1821                         return err;
1822         }
1823         return 0;
1824 }
1825
1826 static int veth_newlink(struct net *src_net, struct net_device *dev,
1827                         struct nlattr *tb[], struct nlattr *data[],
1828                         struct netlink_ext_ack *extack)
1829 {
1830         int err;
1831         struct net_device *peer;
1832         struct veth_priv *priv;
1833         char ifname[IFNAMSIZ];
1834         struct nlattr *peer_tb[IFLA_MAX + 1], **tbp;
1835         unsigned char name_assign_type;
1836         struct ifinfomsg *ifmp;
1837         struct net *net;
1838
1839         /*
1840          * create and register peer first
1841          */
1842         if (data != NULL && data[VETH_INFO_PEER] != NULL) {
1843                 struct nlattr *nla_peer;
1844
1845                 nla_peer = data[VETH_INFO_PEER];
1846                 ifmp = nla_data(nla_peer);
1847                 err = rtnl_nla_parse_ifinfomsg(peer_tb, nla_peer, extack);
1848                 if (err < 0)
1849                         return err;
1850
1851                 err = veth_validate(peer_tb, NULL, extack);
1852                 if (err < 0)
1853                         return err;
1854
1855                 tbp = peer_tb;
1856         } else {
1857                 ifmp = NULL;
1858                 tbp = tb;
1859         }
1860
1861         if (ifmp && tbp[IFLA_IFNAME]) {
1862                 nla_strscpy(ifname, tbp[IFLA_IFNAME], IFNAMSIZ);
1863                 name_assign_type = NET_NAME_USER;
1864         } else {
1865                 snprintf(ifname, IFNAMSIZ, DRV_NAME "%%d");
1866                 name_assign_type = NET_NAME_ENUM;
1867         }
1868
1869         net = rtnl_link_get_net(src_net, tbp);
1870         if (IS_ERR(net))
1871                 return PTR_ERR(net);
1872
1873         peer = rtnl_create_link(net, ifname, name_assign_type,
1874                                 &veth_link_ops, tbp, extack);
1875         if (IS_ERR(peer)) {
1876                 put_net(net);
1877                 return PTR_ERR(peer);
1878         }
1879
1880         if (!ifmp || !tbp[IFLA_ADDRESS])
1881                 eth_hw_addr_random(peer);
1882
1883         if (ifmp && (dev->ifindex != 0))
1884                 peer->ifindex = ifmp->ifi_index;
1885
1886         netif_inherit_tso_max(peer, dev);
1887
1888         err = register_netdevice(peer);
1889         put_net(net);
1890         net = NULL;
1891         if (err < 0)
1892                 goto err_register_peer;
1893
1894         /* keep GRO disabled by default to be consistent with the established
1895          * veth behavior
1896          */
1897         veth_disable_gro(peer);
1898         netif_carrier_off(peer);
1899
1900         err = rtnl_configure_link(peer, ifmp, 0, NULL);
1901         if (err < 0)
1902                 goto err_configure_peer;
1903
1904         /*
1905          * register dev last
1906          *
1907          * note, that since we've registered new device the dev's name
1908          * should be re-allocated
1909          */
1910
1911         if (tb[IFLA_ADDRESS] == NULL)
1912                 eth_hw_addr_random(dev);
1913
1914         if (tb[IFLA_IFNAME])
1915                 nla_strscpy(dev->name, tb[IFLA_IFNAME], IFNAMSIZ);
1916         else
1917                 snprintf(dev->name, IFNAMSIZ, DRV_NAME "%%d");
1918
1919         err = register_netdevice(dev);
1920         if (err < 0)
1921                 goto err_register_dev;
1922
1923         netif_carrier_off(dev);
1924
1925         /*
1926          * tie the deviced together
1927          */
1928
1929         priv = netdev_priv(dev);
1930         rcu_assign_pointer(priv->peer, peer);
1931         err = veth_init_queues(dev, tb);
1932         if (err)
1933                 goto err_queues;
1934
1935         priv = netdev_priv(peer);
1936         rcu_assign_pointer(priv->peer, dev);
1937         err = veth_init_queues(peer, tb);
1938         if (err)
1939                 goto err_queues;
1940
1941         veth_disable_gro(dev);
1942         /* update XDP supported features */
1943         veth_set_xdp_features(dev);
1944         veth_set_xdp_features(peer);
1945
1946         return 0;
1947
1948 err_queues:
1949         unregister_netdevice(dev);
1950 err_register_dev:
1951         /* nothing to do */
1952 err_configure_peer:
1953         unregister_netdevice(peer);
1954         return err;
1955
1956 err_register_peer:
1957         free_netdev(peer);
1958         return err;
1959 }
1960
1961 static void veth_dellink(struct net_device *dev, struct list_head *head)
1962 {
1963         struct veth_priv *priv;
1964         struct net_device *peer;
1965
1966         priv = netdev_priv(dev);
1967         peer = rtnl_dereference(priv->peer);
1968
1969         /* Note : dellink() is called from default_device_exit_batch(),
1970          * before a rcu_synchronize() point. The devices are guaranteed
1971          * not being freed before one RCU grace period.
1972          */
1973         RCU_INIT_POINTER(priv->peer, NULL);
1974         unregister_netdevice_queue(dev, head);
1975
1976         if (peer) {
1977                 priv = netdev_priv(peer);
1978                 RCU_INIT_POINTER(priv->peer, NULL);
1979                 unregister_netdevice_queue(peer, head);
1980         }
1981 }
1982
1983 static const struct nla_policy veth_policy[VETH_INFO_MAX + 1] = {
1984         [VETH_INFO_PEER]        = { .len = sizeof(struct ifinfomsg) },
1985 };
1986
1987 static struct net *veth_get_link_net(const struct net_device *dev)
1988 {
1989         struct veth_priv *priv = netdev_priv(dev);
1990         struct net_device *peer = rtnl_dereference(priv->peer);
1991
1992         return peer ? dev_net(peer) : dev_net(dev);
1993 }
1994
1995 static unsigned int veth_get_num_queues(void)
1996 {
1997         /* enforce the same queue limit as rtnl_create_link */
1998         int queues = num_possible_cpus();
1999
2000         if (queues > 4096)
2001                 queues = 4096;
2002         return queues;
2003 }
2004
2005 static struct rtnl_link_ops veth_link_ops = {
2006         .kind           = DRV_NAME,
2007         .priv_size      = sizeof(struct veth_priv),
2008         .setup          = veth_setup,
2009         .validate       = veth_validate,
2010         .newlink        = veth_newlink,
2011         .dellink        = veth_dellink,
2012         .policy         = veth_policy,
2013         .maxtype        = VETH_INFO_MAX,
2014         .get_link_net   = veth_get_link_net,
2015         .get_num_tx_queues      = veth_get_num_queues,
2016         .get_num_rx_queues      = veth_get_num_queues,
2017 };
2018
2019 /*
2020  * init/fini
2021  */
2022
2023 static __init int veth_init(void)
2024 {
2025         return rtnl_link_register(&veth_link_ops);
2026 }
2027
2028 static __exit void veth_exit(void)
2029 {
2030         rtnl_link_unregister(&veth_link_ops);
2031 }
2032
2033 module_init(veth_init);
2034 module_exit(veth_exit);
2035
2036 MODULE_DESCRIPTION("Virtual Ethernet Tunnel");
2037 MODULE_LICENSE("GPL v2");
2038 MODULE_ALIAS_RTNL_LINK(DRV_NAME);